Which trans to go with

[jaysen71581]

Which trans if better for my rabbit project, looking for MPG and these are the 2 transmissions i have to choose from FF12080 or ACH10124

[BigVWman]

The FF but they are so close it likely wouldn't make much noticeable difference.

[R.O.R-2.0]

i would go with the ACH.. it has the conical washers and all the rest to keep the drive flanges from rattling. not like they ever did, but i would use the ACH.. unless the FF is in significantly better shape..

[jaysen71581]

ACH was dirty but is cleaning up nicely, the FF needed a front trans seal, would you happen to know which timken seal i should get??? i mated the motor with the ACH a few mins ago and i have a little wire brush i am slowly taking the years of crap off it lol....

[R.O.R-2.0]

ACH was dirty but is cleaning up nicely, the FF needed a front trans seal, would you happen to know which timken seal i should get??? i mated the motor with the ACH a few mins ago and i have a little wire brush i am slowly taking the years of crap off it lol....

i have no experience with re-sealing a VW trans. i got no idea what seal to use. theres only 2 different seals isnt there? one for the big input shaft (all mk3, and mk2 16v) and one for the small input shaft (all mk1, and 8v mk2)

[8v-of-fury]

Yup. While you have the trans out and axles off..

It would be wise to do the Input shaft seal, new pushrod (needs to have a cone end for proper clutch operation), Pushrod seal and bushing. As well because the axles are off, the little seals that keep the trans fluid out of the inner CV's.

[Quantum TD]

The FF flange seals are easy to swap. No special tools required other than circlip pliers.

The ACH will require you to buy or fabricate a tool to compress the flanges.

The FF will give you better MPG due to the lower Ring and Pinion. The ACH will give better acceleration due to power at the pedal.

Some later FFs have a .71 5th gear. Yours most likely should have a .71, but may have a .75. It's right on the cusp of the switch.

[Vincent Waldon]

While replacing seals, it's a good idea to do the pushrod bushing and seal as well... a few bucks each but a real pain if you have to pull the whole thing apart again when they go:

[maxfax]

Vince, that's just darned spiffy!!!!

AS far as which trans to use, how will you be driving this car?  Highway, city, or a mix? I've had both an FF with a .71 5th and an ACH in my current car..  My regular diving is usually a 50/50 city/highway and I saw no significant change in average mileage which is around 46..  The FF gave me slightly more mpg (1 or 2 maybe)on the highway, the ACH works a bit nicer on back roads, hilly terrain, and city traffic..  I suspect the non highway mileage is a tad better with the ACH hence no change in the total average...

[BigVWman]

i would go with the ACH.. it has the conical washers and all the rest to keep the drive flanges from rattling. not like they ever did, but i would use the ACH.. unless the FF is in significantly better shape..

Have you ever noticed your drive flanges rattling? The ACH has the *potential* to go self machining the FF really doesn't.

[R.O.R-2.0]

i would go with the ACH.. it has the conical washers and all the rest to keep the drive flanges from rattling. not like they ever did, but i would use the ACH.. unless the FF is in significantly better shape..

Have you ever noticed your drive flanges rattling? The ACH has the *potential* to go self machining the FF really doesn't.

how does the ACH have a potential to machine its self? its not a mk3 trans..

i thought only the mk3 trannies machined themselves?

i have no idea if my drive flanges rattle. i just know the later trannies got more parts in them to make them better. parts that the early trannies did not get..

[BigVWman]

I was just curious i never have either. The self machining trans run from early 84 manufacture till mid 88 iirc.The mk3 trans had reverse idler issues. Personally i have had more issues with later versions (85+)than i have with early ones(79-84) but it could be because of how VW used them sticking basically the same trans into heavier cars.

[burn_your_money]

When choosing a tranny I usually take the 3 speeds I commonly drive at (for me that is 60, 90 and 115km/h) and then I plug them into the tranny calculator on scirocco.org/gears and see what gear and what RPM those speeds will be at. If for example 60 is right at a gear change for one tranny then I probably wouldn't use that one. It also depends on the terrain. You may need more revs going up a hill at the same speed then on the flat for best mileage.

If all you do is city driving then a close ratio gear box will give you the best mileage.

[jaysen71581]

While replacing seals, it's a good idea to do the pushrod bushing and seal as well... a few bucks each but a real pain if you have to pull the whole thing apart again when they go:

The Pushrod bushing, where do i get one of those and how do i take it out, its not in my vw manual.
The ACH doesnt leak abit but i do see it will need the bushing, the FF leaks like crazy at the seal, i got one from autozone but it looks to be the wrong one so im not sure what seal that will need.

[BigVWman]

http://www.fap99.com/ShopByVehicle.epc?q=1982-VOLKSWAGEN-Rabbit--L--Custom/l4_1.6l_diesel_cr&yearid=1982%40%401982&makeid=VOLKSWAGEN%40%40VOLKSWAGEN%40%40X&engineid=1285185%40%40RABBIT+L+CUSTOM%2FL4_1%2E6L_DIESEL_CR%40%40RABBIT+L+CUSTOM&catid=Transmission&mode=PS

Bushing is $1.74 and worth hundreds when it saves you from having to take out the trans again and replace the brand new clutch plate you just covered in oil because the bad bushing screwed up your seal! There are lots of suppliers, FAP is just my personal favorite.

To remove I usually tap it and thread a bolt in then yank it out with hammer but thats my ghetto method!