I took the car out on a 1000-mile trip in 3 days, including two of those being at a work site on Augusta, GA. Leaving from the Florida panhandle, I traveled northeast of Atlanta to meet family for supper, and then drove US78 towards Augusta. US78 is a very nice touring road, with good pavement, sweeping curves and great scenery. After completing work at Augusta, I headed through rural central Georgia to Hazelhurst, where a complete late model Ford 9.75" rear end was loaded into the hatch (for our Ford Expedition - failed bearing). After repacking, I headed home, with many runs to the mid-100's, and an absolutely enjoyable run back home. No major issues, and despite the "foot down" mode of my driving, I still managed to get 19-20mpg. Sure, I could get much more than that, but this at least illustrates the level of fun I was getting away with!

Tomorrow I have to wrap up installing this 9.75" rear end (whole other debacle of a story). Then I will resume work on the HAG210/Wavetrac install. Oh yeah, I forgot about that. I have finished fabricating the case spreader tool for that, and have tested it a bit by spreading the case, and seeing where it returned to. Repeatability seems to be a bit of a challenge, but I am learning the tricks. Goal will be to be satisfied with the Wavetrac install by tomorrow afternoon, and then I will begin bushing replacement in the rear subframe on Sunday. I hope to begin dropping the stock, unmodified rear subframe out of the car by midweek, and get it all back together over next weekend. It is one of the last major projects that I want to do ahead of Tail of the Dragon. I have a right knee total replacement in early September, and won't be able to do a whole lot of this kind of heavy lifting for a while after that!

 

Neil, you do know i have a 3.64 and or a 3.90 diff that is a bolt in and the Wavetrac also fits into the new case i have
just for information the 3.64 is used where the 3.90 is new, for a limited straight bolt in same for the srt6 but i or u have to replace the rear 1/2 of the drive shaft as the yoke is the same as the limited. I now have the rear installed into 3 srt-6 using 1/2 driveshaft
from a srt6 and the rear 1/2 is from a limited ,,,,,,,, jim

 

Thanks, Jim. I am actually going the other way in ratio. Leaving the SRT6 3.07, and going to 2.82. I may even move to a 2.65 in the future. The M113K has way too much bottom end as it is.

 

i have to look but i think i have a 287 in a pumpkin, Used but never opened , it is almost a direct replacement (yoke) two choices replace the rear half of drive shaft or replace the yoke with a srt6 one.

 

Is it a HAG210, with bolt up axles?

 

I looked ,,could not find it, you know we moved from Ft Laud. to Indialantic (Melbourne fl. ) and a lot of stuff is in miami it will be a while befoer i get there to check.

 

Awesome thread! Ive read every post. One question. How would the wobbling pulley cause missfires?

 

Ah! Good question! As I understand it, the wobbling pulley threw the engine out of balance, which the ECU interprets as a misfire situation. The ECU responds by effectively turning off what it interprets as the offending cylinder. This causes more imbalance, and a further bad self-diagnosis of a missing cylinder, so it shuts down another one. It kept doing it until it had shut down 5 of 8 cylinders!

 

30 May 2023
It's been over 9 months since I posted an update, but there are exciting things afoot for this project. The car has remained mostly untouched since the last update, as several other projects have come and gone in the shop, including the rescue of the E55, which had originally been purchased to donate its engine as a spare for this car!

This past weekend, Donna and I took the V8 Crossfire on a tour of Florida's "Forgotten Coast" which is a strip of beaches running from just east of Panama City, FL to the Big Bend area, where the peninsula curves south. Our love for Crossfires runs strong, but lighthouses are what we enjoy the most, so we set out to see the four remaining lighthouses of the Forgotten Coast, and it just didn't hurt to get a few pics of the Crossfire with them!

The Cape San Blas Light, Port St. Joe, FL


St. George Light, St. George Island, FL



Crooked River Light, Carrabelle, FL


St. Marks Light, St. Marks, FL

The car ran flawlessly during the over 650 miles it was driven. It was a fun trip, and I look forward to making this same trip again in the future. If you are ever looking for a really scenic coastal car trip, the Forgotten Coast offers a lot of gems along the way!

In the coming weeks, my family will head west for wheat harvest as they do every year, but I have to stay behind for work. In those times, I have no set schedules or family duties and this becomes an ideal time to take on the really big car projects. Two years ago during harvest, I pulled a well running V6 out of this car, and put a V8 in. This year, I will be pulling the V8 out again.

It actually runs very well, but there have been some lessons learned about long term reliability of the engine, and I want to tackle some of the heavier preventative maintenance. For instance, it is known that the timing cover seals *will* fail one of these days (M112/M112K has this same issue, BTW). This is a major project that can be accomplished in the car, but, there are other items to also take care of. I will also pull the oil pan to replace the oil pump check valve (lesson learned from the E55), oil pump chain, tensioner and spring. The chain gets loose, and slaps around in the M113K. This is a known issue, and easy to remedy once the timing cover is off. Inspection of the timing chains will happen, and I have replacements on hand, if warrented. While the engine is out I will also replace the rear main seal which has been weeping since I got this setup running, It never has leaked worse than that, but time to take care of it. At the same time, I will be adding a beautiful pair of Needswings headers to the package. Other than small maintenance and cleaning, the last engine item will be the addition of a Killer Chiller setup, and with it moving the battery to the trunk to make space for a water tank (which will be added later).

In the rear of the car, I will be dropping the entire rear subframe. This is to install a modified 2005 SRT6 subframe that will feature later model rear differential housing bushing mount points. This will allow the bolt-in installation of the HAG215 differential, which is a project I have wanted to get done for at least two years. I will also add a Wavetrac to the mix, and the rear end ratio will change from the current 3.07 to 2.65. With the extra torque of the V8, it will be better to just slow that engine down a bit. The driveshaft will be modified with MB V8 4 bolt flanges front and rear, too, as I am concerned about tearing up the three bolt type of flex discs.

There are a few other items I will tackle along the way, and I will detail them here. For now, let's consider this the kick off post for the next round!

 

08 June 2023
So it begins! The 2023 "Tech Refresh" for the M113K Crossfire. Each summer, my family heads for the farm in New Mexico for several weeks, but I am left here to go to work, and in my off times, it becomes wall to wall car projects. Two years ago saw the pulling of a perfectly well functioning M112 out of the car, and beginning of putting in a M113K. Last year a 1962 Triumph TR3B got a full engine and mechanical rebuild. This year is back onto the Crossfire. As mentioned in the last post, there are several things I want to accomplish this summer. One will be to replace the stock-type open differential with a much more stout HAG215 differential carrier with a Wavetrac installed, and so that is what was started with.

Here you can see the size comparison between the two, and knowing how small the Crossfire is, you know trouble is already brewing!


This is what a stock differential looks like on the ground, laying in the rear subframe. The subrame is laying on its back, so this is kind of the view you would have if you were looking at your car on a lift



When you lay the HAG215 diff into a Crossfire subframe (and it is indeed R193 specific, not R170!), you see several problems right off the bat



See that forward mounting hole? That's important! The distance between that hole in the diff casing and the centerline of the axle is the same between both types of diffs. That's good news! So, to begin we need the HAG215 to bolt right up on that hole. It is our reference. Everything else needs to move to accommodate. And as you can see above, the diff is larger, so the rear of the subframe will have to move. Time to break out the cutting torch and welder! All the rear mountings of the R193 subframe must be removed so that the mounting portions can be moved aft about 5/8". Did I look to see if this will fit in the car. Yup. It's super tight. Will it fit. Hoping so, but modifications to the car are not ruled out. Hoping a hammer massage is all that is required, but if it needs more cutting and welding, well, we have the technology.

First things first. An R171 rear subframe donated its life after work with a plasma cutter liberated the entire mounting portion for the rear of the differential.

See that extra hole that looks like a third differential bushing might fit? OK, read on.

The HAG215 being used for mock up is from a 2008 Dodge Challenger SRT8. It is the same as found in later W211 E63's and others. This one here is a 3.06 ratio, which was initially chosen to match the 3.07 currently in the car. However, after driving the M113K in a light car for almost two years, the decision has been made to go ahead and swap some guts around with another HAG215 from an E55, which uses a 2.65 ratio. More on that when I get to the point of installing the Wavetrac. In the meantime, the later HAG215 was also chosen to take advantage of the "dogleg" rear mount, which will help prevent wheel hop problems. There are not problems at the moment, but that is probably due to not yet using sticky tires, and not having a LSD. The cutting torch and welder have to be broken out no matter what, so long term success should be baked in now.

Now a similarly shaped but slight smaller hole was cut into the R193 subframe. Hard to orient your eyes at first, but the subframe is standing up, with the rear of it facing up in this picture.


And then checked to see how the new rear plate might sit on it - still a lot of trimming to do, but also spacing it to the rear.


It's going to work, folks! Unfortunately, this part of the project needs to be put on hold. Soon the family will head to New Mexico, and I will be losing my right hand man, @QuadPrism for a while. I wanted (needed) his help on getting the car prepared now, and the rear subframe project will be picked up later. So, the next big inevitable part of this project, drivetrain removal. Here he is running the engine hoist for me last night:


And empty in here once again


Powder coat on the trans held up wonderfully!

Today everything will be power washed, and put back away.

That's all for now. Will post up more in the days/weeks to come. Thanks for reading!

 

13 June 2023
Busy day at work today, so not as much time to spend with the Crossfire. However, the rear subframe was removed from the car, so that part is done.


This is the first time this entire assembly has been out of the car. Overall, everything looks just fine. No rust, and the sway bar brackets look OK on initial inspection. They'll get a close examination before this goes back together.

Next will be the preliminary mockup of the modified subframe, and test fitting of it with the HAG215 in the car. Once everything fits, final welding and then assemble of the entire subframe can take place. Goal is to have it back in the car this weekend.

 

22 June 2023
It's been over a week, and I owe an update. Been putting in long hours on the "2023 Crossfire Tech Refresh Program" (TM), and haven't sat still long enough to give an update. Drivetrain is out, and has been pushed to the side for now while taking car of more chassis/body centric chores that need to be complete before that stuff can go back in. We last talked about the stock rear subframe coming out, to make room for the new and improved subframe that can take several different Mercedes rear ends, including the HAG 215. So, here's where we left off: the new subframe is tacked up and several test fits with the Challenger differential have been completed. Here's what the subframe looked like at that point:

The trick here is that third offset differential mount hole. That mount allows the newer 'dogleg' rear ends. So we're cruising at this point. Perfect time to sit back, take a sip of tea, and decide to scrap it all. Yes, that's right, this subframe was binned. OK, I just moved it to the back of the shop. Everything about it was going to work just fine, but it was just overly complicated. Does this mean we're giving up on the dream of the HAG215? Oh, no, no, no! Now we'll just start cutting up the only other good Crossfire rear subframe left! And that's exactly what happened next. Except this time, the rules would be slightly different. Only the portion of the subframe where the third differential mount is would be cut out this time, and then a lot of measuring, messing up, cleaning up, re-doing and finally that sausage was made!



This was also the proper time to replace the subframe mounting bushings, and so:



I cannot stress enough the importance of having the proper special tools for this job. Doing it without them would be awful. These were purchased off eBay for around $100 per set (there are two sets). These do all of the bushings in the rear subframe, and I believe the front control arms. (Do not replace front control arm bushings - just buy complete SLK320/32 front control arms. You can thank me later)

So now, it was finally time to setup the rearend with the Wavetrac. This went mostly smoothly, with one minor exception. Nowhere does it tell you that the Wavetrac will not fit into the housing as it is. It is physically larger than the stock differential, and you just cannot get all the angles needed to insert it into the housing. I have had similar experiences on other rear ends and transaxles when installing Quaife LSDs in them. The fix is relatively simple, grind a chamfer on the sides of the back side of the housing to allow more angle when inserting the differential. In the future, do a test fit BEFORE the pinion shaft is installed. In this case, everything had to come apart to grind, clean, and then reassemble. Here it is, in place. If you look closely, you can see the chamfers on the rear of the housing:


So now that is done, install it in the frame, right? First the game plan is to use the early style bolt together axle shafts like the SLK, W210 and W208 cars used. Problem is that there are no stub shafts out there for the HAG215, but fortunately an Australian user on MBWorld had made some, so I purchased those.

So now, we need to bolt in the differential, pop in the W210 axles I already had, and go. Yeah, ok


Two big problems. First, the axle is about 1.25" too long. Second, the bolt patterns on the hubs and the axles do not match. *sigh* Back to the drawing board, and about two days' worth of research, looking at junkyard shafts, etc, until a brainwave was had, and we actually went back in time 18 months when the idea of a HAG215 first came to light: A hybrid push-in axle. I had purchased four axles with the idea of coming out with two that worked. Two Crossfire axles and two Dodge Charger Hemi axles. The idea? Take the shaft and outer joint from the Crossfire axle, and the inner joint from the Charger. And this was what had been done, and then the axles were forgotten about when the lure of the ease of maintenance of the bolt in axles and stub shafts from Australia came along. Before putting the axles in, one item needed to be addressed. When the V8 first went into the car, there was an issue with the exhaust. Specifically an SRT-6 exhaust was to be used, but the 2004 limited rear subframe was missing a provision to bolt up an exhaust hanger bracket that the SRT-6 resonator needed. In hast, the bracket was welded to the subframe, and it was a really lousy job. On top of that, the bracket was not in quite the right spot, so the exhaust was a little crooked. Referencing the SRT-6 subframe I had discarded earlier, holes were drilled and nutserts put into the Limited's subframe

SRT-6 subframe with the bolt holes for the exhaust bracket

Out of room for pics in this post, more in the next....

 

22 June 2023 (continued)
So now was a moment of truth, would it all work out? Time to assemble.

Good news and bad news. The good news was that the axle was the right length (23.5" from differential face to the inside flange of the wheel bearing/hub, for reference, BTW). The bad news? Look at that angle on the shaft! There's always some, but this seemed like too much. What was wrong? What that turned out to be was very bad measurement on my part! In the beginning of this part of the journey, I stated in this thread that the distance from the front mounting hole of the differential housing to the centerline of the axles was the same between the stock HAG190 and the HAG215. That is WRONG!!! In all actuality, the distance was shorter on the HAG215 by exactly 10mm. Now there's a problem! The whole differential has to shift aft 10mm to get the axles in the exact same alignment as stock. The straighter you can make CV axles, the better, especially when it comes to launches, however, they are never perfectly straight for many reasons, and even stock the differential centerline is pulled slightly forward of the hubs. So, some trickery was necessary. In this case it was a combination of simply sinking the two rubber differential mounts further towards the rear, grinding clearance on the subframe and the ribs on the back cover of the differential. The front mount hole was also carefully slotted to move that rearwards. The number achieved became 8mm - 2mm less than ideal, but the result looks much better:




Now we're in business! Everything turns nicely, without any binding. A quick check of the pinion angle shows the front flange in exactly the same height position as the HAG190, so good there, too!

Putting a complete subframe into a Crossfire on the ground, without a lift is a chore, to say the least! I was a struggle, but it was finally in there. A quick look around showed one minor issue. The dogleg mount cover was pushing on the body of the car. This is no good for a lot of reasons, especially for NVH issues. Taking the cap off showed no interference otherwise. As the cap just helps protect the rubber from the elements, I simply sectioned the cap:

It's got more room than this picture shows.


One bolt left, and we're done with the subframe! Hahahahahahah! Not so fast there, cowboy! How many times do you think you can put a rear differential bolt into the housing? Answer, one less time than needed to complete the project. As the bolt was being torqued down, aluminum bits started raining down, and suddenly the tightening bolt became loose. Ugh! Stripped! The bolt was inserted to just hold the differential level until a M14x1.50 Helicoil kit arrives on Friday...

Work doesn't stop when things go wrong. Rear brakes were cleaned up and new EBC Blue Stuff pads that were won in last years EBC Halloween contest were installed

Blue Stuff pads in SLK55 330mm rear brakes

The next chapter coming up in the next post.

 

The rear subframe project was a pretty major one. It's not done yet, as the Helicoil needs to be assembled, and the rear section of the driveshaft will likely have to be modified. However that is not going to be looked at until the powertrain is back in the car. One of the next projects to tackle was relocating the battery to the trunk. This is what is being worked on tonight. It is not complete yet, but this brings this thread up to date. Tonight's job was to simply get the 1/0 welding cable being used into the car, and routed through. Work started by disassembling the right side trunk panels, removing the passenger seat, removing the battery and tray, and pulling back the bulkhead and floor carpets. Safety is paramount when doing a battery relocation, so a few tips, if you've never done one. First, try to keep the positive cable away from anything metal that can chafe it. This is not always possible, but for the places it is, do it. Second, once you route the cables, zip tie them fairly snuggly together and to other stationary objects. The more movement can be restricted, the less chance vibration will do its work on them. A big thank you to @stryfox (Carl Abbott) for inspiration on routing of the cables.


There is a small hole through the bulkhead near the right subwoofer. There is a sound insulation piece that needs to come out, but it fits back in when done.





Follow the main cable bundle, but bind up the battery cables to keep them from moving

There is a tunnel under the seat frame. Again, follow the main bundle


Continue forward under the tray holding the amp and TCU

Hold the cables towards the left so that the amp/TCU tray fits back on without contacting the cables

Pull the grommet under the battery tray out that has a single vacuum hose for the HVAC going through it. I will add a grommet to prevent chafe before this is complete


Inside, put the cover back over the wiring bundle. This protects the wires from the passenger's feet


Button up the bulkhead carpet


Lay the floor carpet back down, and put all the covers and door sill back on. You know that carpet is getting steam cleaned before the seat goes back in!

That's all for tonight. Tomorrow a new Optima Red Top Group 78 battery and billet mount will be added to the trunk. This battery was chosen for it's slightly shorter height than the H6, and also the side post battery connections. Up front the ground lead will be terminated and bolted to the car. The positive side will be left for the time being. Once this is complete, a bill of materials will be posted, so that this can be more easily duplicated in the future.

 

Lost for words but pleased to see that a Mercedes derivative can be just as tricky are the original.

 

Nemero I think you know I have a 3.45 diff in my srt6 also getting one for My V8,,, once i have a spacer made the wavetrac fits and i have had no problem getting into the housing .
I also have a 3.67 diff and a 3.90 diff all of these diffs a in cars doing testing one tester did not like the 3.90 , he replaced it with a 3.45 and is now testing ie as soon as snow melts and his track opens I have that 3.90 with tcu for sale fot $1500 , I have 1800 in building it jim

still under chemo and radiation treatment for my throat but two weeks to go ,,,,ups and downs withit , more downs than ups

 

Jim, know you have been working on that that, but this is a 215mm differential used in the factory V8 cars - both MB and Chrysler. Aftermarket support is excellent and it is much stronger than the original HAG190. All of this puts my mind at ease for living long term behind the M113K.

As for ratios, I'm not drag racing, but rather cruising. It has 3.06 now, but will likely drop to 2.65 when a set of gears can be acquired. Before I am done with this round of work, all of this will make more sense.

Wish you the very best with the chemo. Keep fighting!

 

it is good that you are going for the cruising part .. I do have a 2.89 in a standard shift car out there but have not heard from him in over a year. you could start out in 3 gear with no problem,, well u could mess up the clutch if you allow it to slip

I ran my v8 over 1000 runs down the drag strip Yes first with 3.07 then 3..27 and now 3.45 broke one axle( because at that time we had no posi diff so i welded it ,, and got one wheel in the water on a burn out and snap hit dry pavement ,,, then the center bearing on the drive shaft came apart, to the point the car could not go over 3 MPH . then came Oct of last year with my srt6,, street tires, no posi unit of any kind run one 12.008. run two 12.085, run 3 twisted the drive shaft in half. and sometime back a year before the pandemic I had a belt come off and go into the oil pan through the front seal, and that is it for failures, our diff is strong enough. we just need a posi unit in it .
Keepin touch as we both are working a better crossfire

FOUND THE QUAIFE FOR THE 170 see below ,, our diff but have not followed through to, it is available
Quaife parts | Birds
Quaife Merc. Limited Slip Diff. Kit | Birds

 

I have a 210mm diff here, too. I considered the Quaife for that one, and we may still go that route for @QuadPrism's SRT-6, but pretty pricey option. Quaife is a good differential, but not as good as Wavetrac. Their 210mm diff is for a W124, and while it fits the ring gear in a 210, it does not fit the later housing.

 

$1171, - 1073 euro so yes it is more but try to buy a used wavetrac for that amount. I try to work on bolt in ,turn key install and go. with all my diffs they are all that way.
I would like to have a 2.89 in my V8 but only for the 1/2 mile run lol too fast. thanks for your input jim