Transmission rebuild
#76
Former Sponsor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
After two times having the unit apart it is obvious something is more at work than burned clutches. So starting with a good known core that has not failed might be a better course of action. If I wanted him to try again he would. I'm not interested in setting records on the most times removing a 928 transmission.
I've got a transmission I redid still sitting on the stand.....waiting for me to have the ***** to send it back.
It was rebuilt by the "prior 928 transmission guru" and never got installed....the owner has a bad feeling about it and wanted me to go through it and see if it was viable.
What a mess. I would expect any rookie here, to do a better job. Pieces missing, pieces in the wrong spots, O-rings and seals folded over. I don't understand how it would have ever moved a car.
So why is it still here?
There was literally so much wrong, so many little details incorrect, I fear that I might have missed one of the really subtle "land mines", hidden inside. I'd estimate that this transmission took me 3X as much time to do than if I'd done it first, myself! Sometimes I wish I had a transmission dyno. I'm inclined to install it in a car and test it, before I ship it....but you know how much work that is. I threw the valve body that came in this transmission into the trash....it was that screwed up. I rebuilt another valve body, installed it into one of my freshly rebuilt transmissions, and it worked perfectly....so that isn't a variable. (I do this with every valve body that I rebuild separate of doing the entire transmission, before I ship them back, so I know they are perfect).
I do not consider these transmissions to be easy, by any means!
I wish you good luck!
#78
Archive Gatekeeper
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Some of you remember Greg's stash of new automatic transmissions.
https://rennlist.com/forums/928-foru...ons-found.html
About every third time I stop by the shop, there's one of these brand new transmissions destined for a customer, mounted on a stand, in a million pieces. Greg's got them apart, checking seals, clearances, etc. The poor bugger is so paranoid about these transmissions being perfect that he probably looks at more of the (brand new) internal parts than some 'rebuilders' do. Don't want to know how many hours of labor get burned up on these spot checks.....
https://rennlist.com/forums/928-foru...ons-found.html
About every third time I stop by the shop, there's one of these brand new transmissions destined for a customer, mounted on a stand, in a million pieces. Greg's got them apart, checking seals, clearances, etc. The poor bugger is so paranoid about these transmissions being perfect that he probably looks at more of the (brand new) internal parts than some 'rebuilders' do. Don't want to know how many hours of labor get burned up on these spot checks.....
#79
Pro
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Just came in from dropping the pan. It's ugly! Purple fluid with black grit and shards of metal! That's one dead transmission! Time to put another bullet in the gun.
#80
Former Sponsor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
This thing should be filled with a plethora of new pieces, since it was just rebuilt.
Although I'm sure you are discussed, it should be much cheaper and much easier to figure out what went wrong and why.
Starting over with another transmission just buys you a complete new set of potential, unknown problems.
#82
Former Sponsor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Wow! Now that's an "adult" failure!
What are those ***** of debris?
You did clean the lines and the front cooler after the original failure, right? Getting that kind of crap (and your prior crap) out of the cooler will not happen with a simple flush. Ultrasonic clean or replace.)
I'd want to know what, where, and why....
What are those ***** of debris?
You did clean the lines and the front cooler after the original failure, right? Getting that kind of crap (and your prior crap) out of the cooler will not happen with a simple flush. Ultrasonic clean or replace.)
I'd want to know what, where, and why....
#83
Pro
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
That is a close up. That's grit, I think clutch material. The rest looks like shavings of some kind. What I am not sure about is what are the copper looking shards from. They look like the stuff from plain bearings in a motor. We are starting from scratch with a completely different(and known good) transmission and torque converter(which will also be rebuilt) because we are pretty sure there is either a crack or flaw in either the case, valve body or torque converter. Because We have already had two shots at this unit. We are starting with a known good. Im also going to pull the radiator and have it cleaned. If I could get a new one right now from Mark I would. I missed that opportunity a few weeks ago.
Last edited by sstrickstein; 09-27-2014 at 05:00 PM.
The following users liked this post:
gumby928 (01-14-2021)
#85
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hat's off to you for trying. I always knew they were complicated but I am just replacing some seals in the oil pump and I am fascinated by what I see in there. Don't have a clue how it works but fascinated. Looks like a fun exercise, but I'll pass on doing more than what I am.
#86
Pro
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Started on removal number 3! I flushed the Trans lines and cooler with compressed air and Trans cooler flush. Two bottles and all the dark fluid is gone. No metal in the cooler or lines, just burnt fluid. The new Trans will be ready in the next few days. Tomorrow out the suspension comes once more. After this I guess if anyone here in Phoenix needs help pulling a Trans I guess I can lend a hand.
#87
Pro
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Got the Trans back out from wheels down to out of car in 3 hours including flushing the Trans cooler and repairs to a stud! Now I'm waiting for my new biullet
#90
Pro
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Today I performed a extensive transmission cooler and line flush. First I pumped two cans of Transmission cooler flush ( 1 can each direction) through the lines) after that I used compressed air to blow out all residue and cleaner. Finally I pumped two additional cans of brake clean though the lines and again alternating direction, I blew all the residue out and caught it in a clear juice jug. All clean both directions and no residue. No metal shavings or grit made it into the cooler. The filter caught all the really bad stuff in the pan. That must mean the failure was in the unit and the shavings and grit flushed into the pan with the returning drain oil out of the upper transmission. Once I get my new transmission installed either me or Adrian at German Transmission are going to tear down the bad unit and see what the failure was. Once I get that I will report back. I removed all my newer parts from the outside of the bad core today as well: Kick down solenoid and valve, neutral switch, modulator valve and wire harness for the transmission.