DW SD

Hi All,
First post here. Active reader, but have what seems like a major issue.

1951 Ford with an L92 / 6L80e swap. After five months of planning, fabrication, etc. had an anti-climatic test drive. Here's my project for those interested: https://www.icloud.com/photostream/#A855Z2WMGOKzTn

Here's the history:
as I neared being back on the road (one week ago), I ran the engine and trans in gear on my lift (wheels off the ground). Seemed to shift through the gears, but then began to operate in only one gear. Research suggested 3rd and limp home mode.

Yesterday, I took the truck out to add fuel to the corner gas station about 1/4 mile away. Trans shifted up through the gears. Probably hit 25 mph, all seems ok. I get gas, start up and head out. Trans seems now in third.

I drive another quarter mile at 15 mph and turn off the engine. I then hit the battery kill switch for 5 minutes. Turn on and start. Trans now shifts through the gears but returns to LHM. I park the truck in my garage and wait for my OBD2 code reader to arrive.

Reader arrives today. I pull the code and have p0700 and p0777 stored. I called the shop who converted the trans from 4WD to 2WD for me and they said to clear the codes, drive again and make note of when the code returns, etc. *NOTE* The same shop also replaced some of the clutch packs and other seals during their work. Not a full rebuild, but two or three of the clutch packs had some noticeable wear, so we decided to replace those at the time of the conversion.

NOW: the trans seems locked in FWD gears. Reverse works. Drive feels like I have my foot on the brake with full pressure. If I give it some gas, the engine feels loaded down, but with no forward movement. I goosed it to 25% throttle and it broke free a bit. At that stage, I stopped. This was all in my driveway.
After clearing the codes, NO NEW CODES RETURNED. But, I didn't really drive it due to the locked-up condition.


Saw this thread here: https://ls1tech.com/forums/gen-5-cam...e-if-fine.html

BTW - the drivetrain, engine, trans, harness were a matched set. I bought them from Duraburb, who does Duramax Diesel / Allison trans installs to high end SUVs. They do 50 conversion / year and wholesale the removed drivetrains. Eric (the owner) showed me video of the engine / trans idling properly and accelerating up through the gears. I'd not have the same faith in a salvage yard drivetrain.

Thank you all for your thought cycles!

Doug

DW SD

On a side note...
Ken W. (ex-GM powertrain engineer and hot rodder) converted my harness to stand alone. From what I can tell, he did a great job and has been super responsive to my ongoing flow of questions. THANKS KEN! Engine fired on first crank a few weeks back. I think he is a regular here.

Doug

DW SD

May I offer any other info that'd help with diagnosis? Is it possibly a stuck valve body? Seems like two gears are being applied at once?

Thank you!

Doug

DW SD

Talked this AM to friend and hot rodder Ryan V. He knows a lot about the electronics and control computers. He said if the issue was in the harness or electrical I'd be throwing a bunch of different codes.
He thinks to gears are being simultaneously applied causing it to lock.

Am going to disconnect the connector to the trans. Ryan said it should go to LHM and third gear. If it does not theory is something mechanical in the valve body is causing the two gear sets to be applied - IE. maybe debris sticking a piston open??

Of course this is speculation. Neither Ryan nor I are transmission experts. I have a very simplistic understanding of how it works.

WE TODD DID

iTrader: (2)

What is the fluid condition? Sounds like you may have a mechanical problem.

grocerygetter

iTrader: (2)

You need to get in touch with Ryan Stevens on here...GPI maybe his log on.

DW SD

Hi,
Appreciate the replies!
I pulled the pan. There are a few small hard bits in the pan, some flakes the diameter of a pencil lead. And very fine material in the fluid that gives it a dark color. Super bummed. I saw the fluid when the trans arrived from Duraburb. It was admittedly a little burned, but definitely no flakes - the trans shop said the color came from light burning on the clutch packs, but said the hard parts all looked good. The biggest bits were about 5/16" long, long and narrow and thin, not magnetic. Almost look like casting flash, but look like they come from a much larger circle.
Will add a picture or two tomorrow.
Kind of surprised no codes still.

Would be nice to have a failure theory when I deal with the shop. They said they'd warranty their work, but they only changed the output shaft (4WD to 2WD for my application), installed the rear tail shaft housing and replaced the worn clutch packs as well as some seals they exposed along the way. They left the pump alone, saying if it worked, that we should just leave it alone. This is a toy project car for me, so I wasn't so worried about ultimate longevity. Still, expected much more,than 30 minutes of run time with not beyond 10% throttle

Doug

DW SD

Here are the photos that show the metal bits and fluid:
https://www.icloud.com/photostream/#A8GRMtznF1uW4

**note, 30 minutes of run time and about 2 miles.**

TOTAL BUMMER

DW SD

I found him, even sent an email, but it bounced. rhino@gogwatney.com - do you have another email? thank you!

ryanvv355

iTrader: (17)

Doug, I talked with my transmission guy and he said more than likely the installer of the output shaft somehow compromised a seal and there is a fluid leak resulting in the TCU not being able to trim the pressure in range, so it sets the code. I would proceed with taking the trans back to the builder. He mentioned most of the tranny shops out there have not even seen a 6 speed, let alone rebuilt one.

Ryan

DW SD

Hi Ryan,
Thanks a bunch!
I did talk to the shop this morning and explained the condition of the fluid, debris found on the top of the filter, in the pan and suspended in the fluid.

They were apologetic and suggested I bring the unit back to be torn down again. They will do the tear down in front of me (again). Hopefully, something will be obvious upon that evaluation. Will definitely keep the broken seal theory in mind.

I have the trans 75% of the way removed, just need to undo the bell housing bolts and slip it out.

Appreciate your support!
Cheers,

Doug

DW SD

I was down at the trans shop today. They tore it down in front of me.

Found the piston that applies hydraulic pressure to one of the clutch packs with damage.
Aluminum bits were in the pan and a fairly large piece of aluminum from the outer circumference was (maybe 3" long) was hanging on the adjacent drum assembly.
They said they don't know the cause of the issue, but are researching.

Ryan V's trans guy said: "its unnatural damage and was probably caused by improper assembly."

I should have looked more closely at how the drum interfaces to the piston. I don't think the area with damage should make any contact at all. And what is weird is that the parts are all spinning, why would it contact only on one side?

Thanks a bunch!

Doug

DW SD

Thought I'd offer an update. The shop who assembled the transmission repaired the issue only to have it fail again at 60 miles. I decided this project was beyond them, especially after discussing the failure, having them say they will work to resolve and then never heard from them again.
So, I found a new shop....
The new shop found the 1-2-3-4 clutch retainer snap ring had been improperly installed and came out (I've read the TSB about this very issue in all of my online reading and research). In that failure, I lost reverse and part of FWD.

The new shop owner (35 years as owner of his trans business - they do a lot of desert and race vehicles, too) said the damage to the piston (part of the first failure) as shown in the photo was indicative of an assembly error and not at all natural.

Further.....he looked at the piston and pointed out the burn marks on the side where the impact occurred. he said the clutches were obviously slipping and overheating on that side. It was his view that somehow the piston was "cocked" causing the interference with another part and overheating all on the same side.

Any how...
I hope to have the repaired trans back from the shop in a few days. I am having them install Sonnax's line booster kit and GM's pump and seal update. The clutches and steels are all new. I hope to have good service from the unit now!

Thank you all,

Doug