No 1st, 2nd or reverse

[Derail20T]

As the title States I'm having some issues, I don't have 1st, 2nd or reverse gears after a manual to auto swap. Before I installed the transmission I did a few upgrades. I had the center diff welded, put in a translab shift kit, and installed a kiggly front clutch pack. I am running a forced four shiftbox and not using a TCU.
After doing some research and troubleshooting, I have narrowed it down to the valvebody or something internal. The shiftbox is wired correctly and working right.
I can drive the car in 3rd and 4th, but if I shift into 2nd or 1st it acts like it is in neutral and free revs.
At this point I am going to pull the valvebody and have it inspected and check to see if the o-ring is installed for reverse. After I check the valvebody the next step would be to remove the transmission and tear it apart, which I really don't want to do!

Has anyone had this issue before? Any advice would be appreciated!

 

[kiggly]

It is definitely a valvebody problem. It sounds like the shift control valve is incorrectly assembled for the forward gears to not work properly. It doesn't explain reverse though. With the valvebody out you can use shop air to pressure test all the clutches and make sure they apply and release when pressure is put to them and released. The translab instructions show the labeled ports from a lower view to the trans. Just give them air and you should hear the pistons 'thunk' into the applied state and then 'thunk' back to seated after you release the pressure.

 

[Derail20T]

It is definitely a valvebody problem. It sounds like the shift control valve is incorrectly assembled for the forward gears to not work properly. It doesn't explain reverse though. With the valvebody out you can use shop air to pressure test all the clutches and make sure they apply and release when pressure is put to them and released. The translab instructions show the labeled ports from a lower view to the trans. Just give them air and you should hear the pistons 'thunk' into the applied state and then 'thunk' back to seated after you release the pressure.

Thanks for the advice Kiggly! I will check the valvebody and hopefully solve my problem...

 

[snapc3]

It is definitely a valvebody problem. It sounds like the shift control valve is incorrectly assembled for the forward gears to not work properly. It doesn't explain reverse though. With the valvebody out you can use shop air to pressure test all the clutches and make sure they apply and release when pressure is put to them and released. The translab instructions show the labeled ports from a lower view to the trans. Just give them air and you should hear the pistons 'thunk' into the applied state and then 'thunk' back to seated after you release the pressure.

Does anyone have a copy of the Translab shift kit instructions? I am trying to check the clutches as Kiggly described. If not maybe someone can label this photo.

You must be logged in to view this image or video.

 

[Derail20T]

I got these instructions emailed to me from the makers of the translab shift kit. I haven't had the chance to check mine out yet, but it looks like the diagram with the ports is at the end of the instructions...

 

[snapc3]

I am having the exact problem as the OP described. According to the diagram, I found my Forward and 3rd/reverse clutch to apply but leak badly when pressurized with air. Pulled the transmission down to inspect the 2 clutches expecting to find a bad seal. Front clutch looked good, but I found a broken forward drum.

You must be logged in to view this image or video.

I found another thread describing a similar problem here where a broken forward drum was also found: http://www.dsmtuners.com/threads/lost-1st-2nd-and-reverse-a-t-gurus-come-in-pls.470272/

 

[Derail20T]

Thanks for the insight. It looks like I'll most likely be pulling my tranny. At least now you have a smoking gun...

 

[Derail20T]

Well I have come to a conclusion that the problem is internal. I swapped out the valvebody with a known good one and I still had the same issue - no 1st, 2nd or reverse. So I have acquired another auto transmission that is supposed to be good. After I get the transmission swapped out and I find some spare time I plan on tearing the transmission apart to find the problem. It will be good to have a spare!