Benching a tranny

kachemakian · 04-05-2009, 05:26 PM

OK, so maybe I won't have to bench press it to change it out but this is the deal- I have had my 914 since 1985 and finally have it close to being able to drive it. 5 years at the body shop etc. I have a 1.7 in it that runs decent with a single carb, a complete 2.0 in unknown condition with all of the parts to rebuild it except heads, but it could be just fine the way it is as it has been stored indoors for 20+ years, and 2 other 1.7s that don't run. I have a side shifter tranny with the 2.0 and the tranny in the car won't go into 3rd, 4th, or 5th. I have 2 other rear shifters and would like to know if there is any way to bench test them to see what the condition of the syncros are. Can this be done? And how hard is it to change the tranny without taking the engine out with it?

Leon

Dave at Pelican Parts · Dave at Pelican Parts's Garage

It's easy to remove the trans without removing the engine. Take the muffler off, loosen the engine mount bolts, support the rear of the engine, unbolt the starter and the CVs, unhook the shift rod, speedo cable, and reverse lights, and unbolt the trans mounts. Lower the tail end of the drivetrain a little for clearance, pull back, and the trans will drop right out. (Maybe a good idea to have a jack supporting it when you pull it out.

Unless you like bench-pressing it!)

Lining up the splines on the input shaft to those on the clutch disk can be more challenging...

No real idea on how to decently bench-test the trans.

--DD

jhora · 04-06-2009, 06:52 AM

As Dave said you can remove the tranny by itself....done it a few times that way thinking I was saving time....but really only two more bolts and a few wires and the whole package comes out....easier to disassemble on the ground when out....that way you're not having to wrestle the starter and align the input shaft while balancing in the air....

jhora · 04-06-2009, 06:56 AM

Oh...as for a bench test on the tranny....not really....it's obvious if you can't get it into gear some thing may be wrong but to really see if the teeth and syncros are any good you have to crack it open and take a look....or your test will be after you do all the work of installing it and the first drive will test it.....good luck!

kachemakian · 04-06-2009, 07:54 AM

Yes, the "find out after you install it" is what I am trying avoid. I may crack one of the spares open and maybe do the "file the synchros" trick. This will be a temp tranny but I would still like it to shift right.
Leon

jhora · 04-06-2009, 11:23 AM

Leon...have you checked all the shifter bushings and adjustments?

kachemakian · 04-06-2009, 06:47 PM

No I have not checked the bushings and adjustment. The car was previously wrecked very bad on both ends with the transaxle and engine shoved forward and the engine cross member/mount bent. I have replaced the engine and transaxle with another one from another car just to make it mobile and it does not shift into all of it's gears. Maybe I should unhook the shift linkage from the rear end, jack the rear wheels off of the ground and have someone else operate the clutch while I try shifting it from the rear. Might be that the tranny in it will go into all of its gears?? Leon

jhora · 04-06-2009, 06:54 PM

That is a very good idea to start with....I think from what you said about the accident situation there may be a number of things creating the problem....

red-beard · red-beard's Garage

The best thing to do is to pull the tranny apart, and pull the gear stack and inspect it. You can actually pull the gear stack, and leave the case attached to the engine!