Kingsize

iTrader: (13)

I recently did an A4 auto swap with a built FMVB 4L65e, no electronics, vacuum modulated. In the vehicle it came from, the transmission worked fine. After the swap, all seemed to work fine for a while, basicly 2 days, but then I started to loose 4th then 3rd, or I thought. While reverse, 1st and 2nd function as normal, once shifted into 3rd it seems to free rev. I assumed the 3-4 clutch issue, but once it slows down, you realize you are back in 1st on the 3rd gear selection, and is functioning as 1st would normally. Once you shift to 4th, it then shifts into 2nd again, and functions as 2nd would normally. WTF?

I can't figure this one out. I've removed, inspected and cleaned the VB. I did find a broken Transgo "White" spring for the 3-4 valve on the FMVB kit, and it was replaced, but the transmission continues to function in this way. Fluid does not smell burned at all, and there was nothing but a small, very slight amount of gold particulate in the pan. What I would consider normal wear.





Anyone have any clue as to what may be my issue? This has me completely baffled. The only change from his car to mine was a Circle D 5C converter.

Jason

bbond105

Just to make sure I understand. You installed a used trans with a FMVB? Has it been rebuilt? Who rebuilt it? How many miles are on the trans? Have you put a pressure gauge on it?

Kingsize

iTrader: (13)

Yes. Transmission literally came out of my friends car, and was bolted into mine. No issues prior to swap. FMVB had been in the transmission. No changes. Pressures are normal with my gauge.

bbond105

I don’t have any experience with a 4L65E FMVB. I understand it doesn’t shift via a PCM but do you have to manually shift it for every gear change or can you just put it in drive and it will shift on its own? From your description, it sounds like it shifts to 3rd gear but the 3-4 clutches are not holding. The higher stall and horse power may have done the 3-4 clutches in.

Kingsize

iTrader: (13)

Yes, manual shift for each gear selection. And after speaking to a few folks, it does indeed seem what I originally thought, is the issue with the 3-4 clutch pack. Sucks, but I guess it is time for a rebuild. Thanks for your help!

Jason

bbond105

Sorry it went south on you. Are you going to do the rebuild yourself?

Kingsize

iTrader: (13)

I was going too, since I've been in 400's and PG's. But they are fairly straight forward in comparison. I may still, but I am currently looking at builders.

bbond105

Buy a good manual and you’ll be okay. The main thing that is different is the input clutch drum; there are 3 different clutch packs in there and a sparg.

performabuilt

iTrader: (25)

I am assuming you do not have the harness plugged in this will cause odd things. But with FMVB is something happens to the 3-4 clutch you will indeed end up with a manual 1-2-1-2 shift which would make the 3-4 clutch the suspected culprit.

Kingsize

iTrader: (13)

Thanks!

Correct, no harness at all. Thanks! Seems I'm hearing this in unison. Glad I at least know the issue. Had me stumped for a bit after I had originally suspected the 3-4. Never seen that behavior in any other transmission before.

You work on manual valvebody A4's? Or want to?

Here is the transmission. Also has rear fluid feed.

mrvedit

If you want to try the rebuild yourself, here is a thread in which I gave advice on books, tools, etc:

https://ls1tech.com/forums/automatic...questions.html

Threads on rebuild Kits:
https://ls1tech.com/forums/automatic...-kit-help.html
https://ls1tech.com/forums/automatic...-problems.html
https://ls1tech.com/forums/automatic...-rite-kit.html
https://ls1tech.com/forums/automatic...ild-4l60e.html #5