Transmission Question?

[BlastIt]

I have an 82 Rabbit pick up with a FN transmission. 2nd and 3rd gears are now grinding on up shift and down shift. I also have a FF transmission laying around. Would the gears interchange between the 2 transmissions? I thought i would just swap 5th gear from the FN to the FF. Is it worth it or a waste of time?

[Rabbit on Roids]

just swap in the whole FF. why go thru the trouble of opening one up when they have such a close to the same fifth gear?

they most likely are the same fifth depending on the year. but if you want, go ahead and swap your fifth gears, count the teeth while your at it, there going to be the same or extremely close.

so why not just save some time, bolt the FF in like it is, and forget about it?

if one is from pre-80, its gonna have .76 fifth gear. if its a post-80, then its gonna have the .71 fifth. the difference is 40 RPMs at 70 mph. so it it really a big enough gain to even swap out the fifth gears? you decide..

[rs899]

without looking at the charts, IIRC final drive is different between FF and FN so I think FN cruises lower.  I had an FF in my pickup when I got it and swapped in a late FN and it was quite a bit better.  That said, swapping 5th doesn't look easy at all to me, and I have rebuilt gearboxes before.... up to you- what your tolerance for pain?

[BlastIt]

Thanks guys. I'll swap it a see how it goes.

[Rabbit on Roids]

ff, fn, fj, fh and fo transmissions all have 3.89 final drives. the only difference between any of them is the 4th and 5th gears. some had .97 4th, some had .91 as for fifth, some had a .75, while others had a .71, and i am pulling this info off scirocco.org's gear section. all these trannies are damn near identical.