2ML70 Rebuild

[Knagawa350]

Hey all! I have an ‘09 Tahoe hybrid, the 2ML70 is slipping the 1-3 clutch and 4th clutch. Chevy is only offering to replace it for 6k and up to a year for the part. All the transmission shops in Portland told me kick rocks and I won’t find the parts. I got this truck a week and a half ago, and I’ll be damned if I just toss that money away. Currently have parts showing up tomorrow from Michigan overnight. SMC performance has OEM original in packaging surplus parts for the 2ML70. I got an inventory list from them, and dug through parts numbers with vague discriptions. However they did have the bulk of necessary parts I was able to verify through GM. The rest I will make sure to check and get a list running on what’s what, when I disassemble. Also (alldata) has a manual online I will be following for this procedure. I’ll post pics for everyone here on this thread, and try and spread any knowledge I have on this subject to those who want/need it.

 

[j91z28d1]

much appreciat the build thread.

I know you said you had a shop confirm the slipping, do you know what they looked for? used a scanner or just drove and felt it?

 

[Knagawa350]

Used a scanner and road test both at the Ron Tonkin Chevy dealership in Portland Oregon, code was: P709D? I can confirm and send a photo of the paperwork when I get home tomorrow morning

 

[j91z28d1]

ahh just looked, yep. P079D is 4th gear clutch slip.

incase you haven't seen it floating around. it's posted a few places. there's a good pdf that tells what conditions need to happen for most code to be set

 

[Knagawa350]

Awesome! I had not seen this yet, I appreciate it! All the parts will be in by 9pm, I get off work at midnight and I’ll be posting pictures of what they look like in the packaging.

 

[j91z28d1]

definitely looking forward to pics.. this tranny is like a Phantom on the net lol.

 

[Knagawa350]

Update: transmission is pulled and on the shop table, I had to leave for work so tear down and rebuild will be tomorrow along with install. The service manual is not ideal for steps to removing transmission, ie. front sway bar needed to be removed to remove the front drive propeller and some other finky little things of that sort.

 

[j91z28d1]

any luck?

 

[Knagawa350]

So caught a snag getting the first electric drive motor out, it takes a specialty tool that is around 1k, so looking into at home shop techniques ie. A chain and some s hooks attached to a motor jack.

 

[Knagawa350]

Also oddly enough the torque dampener (since it is jot a converter) is magnetically stuck on to the front by the 1st position drive motor.

 

[j91z28d1]

hopefully you find a cheaper way to get it out. I never noticed on this tear down video at the 11min ish mark, they do a cut from him trying to get it out, to it just pulling out.

which they would have showed what he did.

 

[Knagawa350]

So we made some progress lifting it and hammering around the outside of the transmission, but not fast enough. Going to a hardware store for a pulley system to use the lift to slowly pull the the motor from housing while flat on the floor. Planning on chaining the trans down to one leg have the pulley on the opposite leg and run the chain up to the lift arm. Then run the lift up to slowly pull the 1st drive motor out

 

[j91z28d1]

wow it's really stuck in there huh. hopefully that works.

what's the 1k$ puller look like?

 

[Knagawa350]

It’s just a hoop with three hooks and a place to put a chain. Got some hooks and connectors to make the same thing with a chain. Ended up having to wedge the casing under a lift arm to hold it down while using a cherry picker to add tension, while tapping the casing with a rubber mallet where it connects to the bell housing. Got her out though.

 

[Fless]

View attachment 417292It’s just a hoop with three hooks and a place to put a chain. Got some hooks and connectors to make the same thing with a chain. Ended up having to wedge the casing under a lift arm to hold it down while using a cherry picker to add tension, while tapping the casing with a rubber mallet where it connects to the bell housing. Got her out though.

A baby is born...

 

[j91z28d1]

glad you got it out.. that's cool.

find anything damaged inside beside cluch disks?

 

[Knagawa350]

glad you got it out.. that's cool.

find anything damaged inside beside cluch disks?

Clutch discs were fried, also the sun gear planetary system pins were torn up and fell right out as well as the the locking spacers. They are hard to find, a used transmission shop here in Portland had a 2ML70 used in the warehouse, they are pulling the assembly for me to see if I can rebuild from that. Otherwise it’s 550 at SMC performance for a new unit. After that I should be able to finish and seal the transmission and get her back in.

 

[j91z28d1]

bummer the hard parts are worn out. I guess at least you're able to find them new as a last resort.

is that the same part that fell apart in that video of them taking that one apart? the pins the smaller inner gears ride on? Wonder if it's a common issue with these

 

[Knagawa350]

First picture is what the retaining washer is supposed to look like, second one is worn. Sonnax is a parts company that has a sister company in Portland (Transtar) who had the 2ML70 washers on their website. Sonnax also said they had them, but differed me to transtar.
They didn’t have them and after taking measurements, they are close to the same first position planetary assembly in the 2L60e but slightly longer. Conveniently next door was a used transmission shop that also partners with transtar. They happened to get a 2ML70 a couple weeks back and pulled the whole assembly for me. It is also worn pretty bad in spots, but does appear that I will be able to refurbish something out of both sets.

 

[Knagawa350]

bummer the hard parts are worn out. I guess at least you're able to find them new as a last resort.

is that the same part that fell apart in that video of them taking that one apart? the pins the smaller inner gears ride on? Wonder if it's a common issue with these

The one he had that fell apart was the second assembly, mine looked used but not falling apart the washers all have the retaining tabs in place