Hey everyone, so im working on my project FD and have a few questions about the transmission and diff. I have never had the chance to drive this car so i dont know the previous condition of the tranny and diff. Transmission is on my work bench and the diff is in the car. Ill start with the transmission (I havent done anything to it including not changing the fluid yet). ok problems ive noticed with the tranny:
1. Its hard to shift into and out of 1,2,3,4. even shifting neutral between those gears seems to have resistance, it just feels extremely stiff between and going in and out of those gears. 5 and R engage easier and disengage very smoothly with one finger.
2. rotating the input shaft to the trans. it seems that i have a few degrees of movement or slack before anything inside is moving. if i move it back and fourth quickly i can hear the gears clack (seems that there is just slack but this may be normal... i dont know thats why im asking).

Diff:
Laying under the car (wheels are off the ground) and rotating the input shaft to the diff i notice the passenger side half shaft push out laterally (away from the diff towards the wheel) with maybe 2-3mm max separation (i didnt measure it but can if need be). The half shafts seem to rotate alright to me. rotating the input shaft in the opposite direction i have the same situation but the drivers side half shaft moves out maybe 1mm. i would assume that there should be NO lateral movement but again i have no idea.

Lastly, this car is being built for a 20b (im planning on moderate power for now on the stock twins... nothing too extreme) but i want to make sure the driveline components are all in good shape (or at least within acceptable operating specs) before bolting everything together and dealing with broken parts as an afterthought. BTW I'm not planning on dragging or hard launching the car at all. if you can give me some pointers, things to check/measure, or have some ideas on the issues ive found, i would really appreciate your input.
thank you, Heath

 

I'll speak about the tranny only. Remove the bottom cover to the center box and inspect. Better yet, post a picture.

The backlash in the tranny gears should be quite small, a tiny fraction of a turn. Maybe a minute on the clock face.

Dave

 

This is the case with both my current and previous diffs. Both are fairly high mileage (around 100K miles). I asked around but nobody seemed to know why this would happen or if it was really a problem. I noticed it when I swapped in a whole new diff assembly (incl housing), then I checked the old one and it did the same thing.

 

ok maybe the backlash is within spec... i dont know... its maybe 5 degrees. its really the super stiff 1,2,3,4 that im wondering about now. if i pull the cover what am i looking for as a cause?

 

Metal chips. They can jam up all kinds of things. Of course they indicate damage too.

If you have a camera and can take a few good pictures that would help too.

 

ill snap some photos once its open. to reseal it its just silicone correct?

 

Yep

 

cover is now open, i honestly dont know what im looking for, but heres basically everything i can see. to my untrained eye nothing much looks out of the ordinary.













[IMG]http://img.photobucket.com/albums/v290/rotormotor/20b%20build%20propgress/IMG_2374
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so would anyone know where i should start if its really stiff to shift into 1234, but not 5/r

also ive noticed, there seems to be a ton of resistance (just turning the input shaft) for 5 & R but not for 123&4. could be related... but its another problem i just discovered.

 

The good news is your 1-4 center section looks good. That's the expensive end.

The not-quite-good news is that I would now take apart the extension housing and 5/R housing and clean that out. I'll bet that something is in that housing that blocks the 1-2, 3-4 selector forks and slowing the 5/R gears. You might have synchro parts floating around, or something else.

Dave

 

any reason it would be really tough to shift into/out of 1234 and not 5/R?
i think i might have to take this to a transmission shop

could it be that its just say dry for so long? what could cause that binding?

 

I find that letting a tranny sit for a long time does not affect shifting. The shift rod races always stay oily.

The work to check out the 5/R end is basically the same as doing a 5th synchro replacement. It's up to you whether to screw around with it yourself. I think it's do-able, others don't want to do it. A good tranny shop should have no problems finding/fixing the problem.

Rebuilding the center case is probably better done by a rotary shop (pineapple, KD, pettit, etc) because it helps to have some special tools for that.

Dave

 

thanks for the advice! i have a local shop thats gonna take a look for cheap, and let me know what they think. ive used them before for other cars and they re very honest (which is hard to find) ill post details of what unfolds