BLKROKT

I’m dropping the beast off tomorrow for a transmission rebuild. Made it almost 40k miles, probably half of those on track. Pretty much every gear change slips, as well as from a roll at low-RPM in the higher gears.

Will supply the AMS/EXEDY upgraded clutch packs. Already have the Weistec TCU/VB and trans pan upgrades. Will probably have him install an auxiliary cooler/fan/pump while it’s all apart and easy to access on a lift.

Is there anything specific that I should ask for, or make sure is done to make it truly bulletproof? I’ve read up a bunch on the 722.9 weaknesses, but it would be great to hear from some of the experts here who have rebuilt theirs to know exactly what to be aware of.

TIA

roadtalontsi

you sure it doesn't just need the mct unit replaced? Pretty hard to kill all the clutches. Mine always kills 3rd gear. You would never know there was anything wrong unless you knew how hard the car should pull at full throttle. At normal throttle it would drive completely normal and shift great.

BLKROKT

That sounds pretty close to what’s happening with my car. When the trans is dead cold it shifts extremely poorly. It then feels totally ok around town once up to temp. But once you really get on it, the pull isn’t quite there, and shifts under load don’t bang at all like they used to - I’d say shifts are 5-10x longer now with noticeable slip when finding the next gear. Unfortunately I think it would be noticeable to anyone driving the car.

Explain to me the “MCT unit replaced” part please? A buddy told me to possibly look into replacing both the wet clutch and front pump. You think that’s the more likely source of the problem?

I have the clutch packs so they’re going in regardless. But I’m not 100% sure that what’s in there is no good. I also don’t want to have to do this again for a long time. So they get replaced either way - better is good.

He also said normal stuff you’d expect in a rebuild like clean out the VB solenoids, replace the Teflon rings on the shafts, and look for any wear or heat damaged parts and replace with new if necessary.


Sound about right? Thanks!

PeterA90

With the track abuse you do to the car... you might as well consider this:

https://southernhotrod.com/shr-war-viking-722-9/

Way more throughly done. And, you’ll have a piece of mind.

BLKROKT

Yeah I thought about that, but I’d have to ship the trans to Louisiana which sounds expensive and unnecessary. Still an option, let me talk it through with my guy tomorrow first. If he’s using Weistec’s old trans man like I think he is, I’ll feel better about it. Of course, then I still have these clutch packs here. Want em?

EDIT: They also sell just their kit which is more comprehensive than just the clutch packs. Kinda like what Weistec used to do. Maybe I’ll use the AMS/EXEDY packs with the rest of this kit. I’ll check this out, thanks dude.
https://southernhotrod.com/shr-merce...nsmission-kit/

Diabolis

I have ZERO experience with the 722.9 so take this with two grains of salt, but based on what little bit I know about how it works, I'd tend to concur with roadtalonsi here. It would be rather unusual to burn up all the clutches. If it's temperature dependent and affecting all gears I too would make sure to look at the hydraulics and components common to all gears, namely pumps, MCT clutch pack as well as TCU in addition to the individual clutches. The fact that it's temperature dependant would seem to indicate that it can't achieve the required clutch pack fill times and pressures when the fluid is cold. And, make sure to reset and redo all TCU adaptations as it will otherwise burn up your new clutches in no time.

cornerjunkie

When I had slippage in 3rd and 5th gear, they replaced the solenoids that were in bad shape and that did the trick. You may have already beaten that horse, though.

hachiroku

the shifting issues you all are describing are mismatch between ECM calculated load/torque values and expected load/torque values expected of the transmission control unit (TCU). with a mismatch no transmission no matter how its built will sustain the advanced wear.

BLKROKT

Thanks a lot for the suggestions guys, really helped me be more educated as to what to look for and ask about.

Car is dropped off and trans will be removed and disassembled soon. We’ll see what they find, they’ll take lots of pics and are pretty excited to see how far I’ve destroyed it. They agreed that any component showing any sort of wear or damage will be replaced or upgraded if possible. I’m psyched just to get to this point - these guys are super AMG nerds with a sterling reputation. They’re also going to plumb in the CLK BS rear diff pump/cooler during the downtime as the trans will be elsewhere. They just happened to have a CLK BS with the track pack up on one of the lifts today (getting an ESS supercharger and headers installed, sweet), and will use that installation as their template.

Feel like I’m in good hands, stay tuned.

roadtalontsi

2212500301 is the MCT part number. Just replace it while you've got the transmission apart. It's quite cheap for what it is.

BLKROKT

Good looking out, thanks. That’s the right thinking - just replace everything.

Question. Besides the upgraded clutch packs, what other improvements can be made while it’s apart? I see the SHR and Weistec kits come with all sorts of other things like:

• Machined K2 piston
• Machined K3 piston
• MAX Capacity K3 clutch support
• B2 top steel
• MAX duty O-ring and seal kit
• Filter
• Intermediate plate
• MB aluminum Valve Body bolts
• MB aluminum Bell Housing bolts
• MB aluminum pan bolts

I’m in marketing. That mostly sounds like marketing-talk. Am I wrong? Is there anything amazing on that list? What other secret tricks do they do in there to justify $4k+?

hachiroku

i see nothing not standard here. you can purchase raybesto's plates from almost any retailer. these parts have been out for some time now. it seems all they do is simply refinish/reman the K2, K3, and K3 Clutch Support pieces. i bet there isn't much to be done other than a nice buffing on a wheel if the transmission is still in good order. enough with this damn AMG tax already. the reason why we don't have more high HP vehicles out there is because all these guys are charging us AMG tax which hurts us in the pocket book from spending more on other things we want or need.

https://transmissioncenter.net/shop/...z-025-2004-on/

Mercedes GPZ 722.9 Clutch Pack Module #RGPZ-025 2004 On.

$ 379.00

Add Steel Module #STMMERCE13 $55

Add Overhaul Kit #88002 $137

Overhaul Kits (w/ Rings & Seals), 722.9 2004 On. Will not fit All-Wheel-Drive.
Options total:$ 192.00Grand total:$ 571.00

$379
https://www.raybestospowertrain.com/...packs/rgpz-025


$55
https://www.raybestospowertrain.com/...cks/stmmerce13

roadtalontsi

it's really not an amg tax. It's just mercedes parts. A mercedes isn't a kia or chevy. Labor just keeps getting more expensive. Not many people can properly or successfully rebuild things anymore. My only thoughts on the raybestos kit is did they actually do a comparison to OE mercedes parts? doubtful. 20% is quite a bold statement, but i'm sure they dont have to abide by the same standards of manufacturing materials as the OEMs. There is also large false assumption that all 7 speed transmissions share the same number of clutches. Interesting they stop at 2013 model year. 9spd didn't really become standard till 2018 in most models.

hachiroku

I'm sure the 20% increased durability is a blanket number, but their GPZ line is their performance clutches for heavy duty or high HP applications. I don't doubt they perform as expected.

GPZ FRICTION CLUTCH PLATES FOR 10R80, 10L80, 10L90Raybestos Powertrain GPZ friction clutch plates greatly increase transmission performance and durability. This state-of-the-art friction material far exceeds OE material to withstand high stress, high temperatures and repeated cycling. Plus, its performance improves as the power increases. Find new GPZ friction clutch pack modules for Ford 10R80, GM 10L80, and GM 10L90 at a distributor near you:

GPZ FRICTION CLUTCH PLATES
Enhanced Performance
Raybestos Powertrain GPZ friction clutch plates greatly increase transmission performance and durability. This state-of-the-art friction material far exceeds OE material to withstand high stress, high temperatures and repeated cycling. GPZ's outstanding performance benefits are perfect for heavy-duty vehicles and high-stress driving. Testing of GPZ revolutionary friction material shows that it outperforms OE materials by as much as 20%. Plus, its performance improves as the power increases. Notable available applications include Chrysler 68RFE, Ford 6R80, Ford 10R80, and GM 10L80, Mercedes 722.6, and ZF Chrysler 8HP90.

Recommended Use:
Heavy-duty vehicles, commercial vehicles and high-stress driving

THERMAL BREAKDOWN
Friction Comparison - FahrenheitGPZ Thermal BreakdownFailure and deterioration under extreme heat.Failure and deterioration under extreme heat.Integrity maintained under extreme heat.

hachiroku

hachiroku

swedepat

Have you guys read up on using blended transmissionfluid with hydraulic oil?

It´s a cheap way of getting rid of slip, but it might do some more wear on parts in tranny, i dunno, but choosing the correct hydraulic oil might even be better, i dunno, but i do know that many transmission professionals offer special blends of oil.

The Machinist

Not an AMG tax, just a Euro tax.

I had $3100 into the overhaul on a ZF 5HP24A with me doing all of the R&I labor (17 hrs worth)

Theres nothing special about any of these parts. Just steel bands and friction discs squeezed together by hydraulic slave cylinders.

GM, Ford, and Chrysler have all used ZF, Getrag, and other German gearboxes and none of those seem to cost as much to overhaul.

In the manufacturing industry, if you can spec out and outsource a specialized part like a clutch disc to a company that does nothing but clutch and friction materials, that’s what you do.

You don’t reinvent the wheel when someone is already selling them. You just tell them what size and width you want.

It’s why I buy a lathe and a grinder instead of building my own from scratch. Could I build one? Maybe??? Could I buy one cheaper from someone who has been building them for 75 years? Definitely.

I found this out with Hydraulik Ring. It’s why AMG and Volkswagen Group contracted them to build cam adjusters. That’s what they do. Poorly.

Can you go to Hydraulik Ring and buy them directly? No. They signed an exclusive manufacturing and sales contract with AMG and VW so that AMG and VW could mark them up 10,000%

BLKROKT

Little update. Transmission has been rebuilt. All of the mechanical internals - wet clutch, solenoids, etc - looked great like new. The clutch packs however were burnt up, and there was material in the pan and throughout. Unfortunately it appears that the last time the trans service was done, the wrong filter was used (older 722.9 type), which may have compromised fluid flow causing the problem. Anyway, comparing the OEM packs to the AMS/EXEDY ones, the only difference seems to be a more robust heavy-duty material construction on both sides of the discs as opposed to just one side on OEM. Will have pics soon.

HLG600

The filter for the non-MCT 722.9 is Part # 2212770200. Is that what was used?

The correct filter for the MCT 722.9 is Part # 2222772000. Mercedes specs it for any 722.9 that came filled with the newer blue fluid from the factory, but it (filter only, not fluid) is backwards compatible (FCP even sells it as an upgrade kit).

For reference:

Standard 772.9 Filter - https://www.ecstuning.com/b-genuine-...er/2212770200/
MCT 722.9 Filter - https://www.ecstuning.com/b-genuine-...er/2222772000/
FCP's Kit (Any 722.9) - https://www.fcpeuro.com/products/mer...n-001989680310

BLKROKT

No idea, I haven’t seen it. I was just told that the guy was shocked to find the wrong filter in there. I’m even more shocked as I trusted my former East Coast shop completely, and they had been absolutely perfect spot-on everything I had ever brought to them.

HLG600

Well damn...if the tech was shocked then it may have been more than just a 722.9 MB part mismatch (the filters look basically the same and the older one even had an overlap of use with the MCT for '09 in the E63 and SL63).

That, or perhaps the older filter with the newer fluid is what caused the failure. Such a bummer to hear that, especially knowing the shop referred to.

At least your transmission is now nearly-indestructible.

BLKROKT

Yeah bummer but I’m looking forward to moving past this with a better than new trans. They didn’t replace the wet clutch itself or any of the pistons - I thought this was a little odd considering that there was clearly heat damage as it was mentioned that the clutch packs were heat discolored. I wonder if I should ask them to replace everything before it’s buttoned back up? I might have time, but without more info I can’t really tell them what to do here. I told them I wanted it bulletproof, yet some things are considered ok and being left as-is. I wonder if this is the best course of action, I don’t want to do this again...

hachiroku

I'm assuming they also disassemble the valve body to clear any debris/dirt between solinoids, check valves, springs, etc. If so, you'll have a mean shifting transmission when combined with the upgraded clutch packs.

BLKROKT

They didn’t touch the valve body as it had already been modified by Weistec and they didn’t want to potentially mess that up.