On our recently converted 4 speed, 300DT (123 body from an '82 240D), we are not thrilled with the differential ratio. Basically, you can start in 2nd gear and of course 4th gear whines with high rpm's.

QUESTION: Of the following options, which would you recommend?

Option #1 - Differential from an '83, 300D Euro 4 speed

Option #2 - Differential from an '83, 300DT

My current understanding is that the chassis we are driving on now has the 1:3.69 (still from the 240).

According to specs, my '83, 300DT parts car offers a 1:3.07

However, I can't find the specs for a euro 300D 4 speed????

Any advice? (The differential is off now and waiting a replacement. What a pain were the four upper bolts....)

Thanks

Don

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DAILY DRIVERS:
'84 300DT 298k (Aubrey's)
'99.5 Jetta TDI IV 251k (Julie's)
'97 Jetta TDI 127k (Amber's)
'97 Jetta TDI 186k (Matt's)
'96 Passat TDI 237k (Don's
'84 300D 211k Mint (Arne- Undergoing Greasecar Conversion)

SOLD:
'82 240D 229k (Matt's - Converted-300DT w/ 4 speed

Don't know the ratio for the euro, but it should be stamped into the rear of the housing. Look on the rear below the rear cover on the drivers side.

I have considered changing my 3.07 in a 80 300SD to a 2.88 for better cruising rpm.

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1980 300SD Manganese Brown Metallic Clearcoat 248k
1979 300SD White 148 k
1984 300D Silver project car for daughter
1982 300D wrecked
1980 300SD 310K not running

Thanks:

I'll check out the cover and probably take the lower of the two.

Don

__________________
DAILY DRIVERS:
'84 300DT 298k (Aubrey's)
'99.5 Jetta TDI IV 251k (Julie's)
'97 Jetta TDI 127k (Amber's)
'97 Jetta TDI 186k (Matt's)
'96 Passat TDI 237k (Don's
'84 300D 211k Mint (Arne- Undergoing Greasecar Conversion)

SOLD:
'82 240D 229k (Matt's - Converted-300DT w/ 4 speed

JUdging by how my friend's Euro 300D drives, I think it has the same gear ratio that the U.S. non-turbo 300D/240D's have.

I would go for the 2.88 if you can find one; your acceleration will be slightly lower, but it'll make up for it in lower cruising speed. On a straight freeway run, I can get 30mpg with my car.

BTW, with the 2.88's and a slushbox, I'm at 3000 RPM at 70mph...

The only problem with 2.88's is that I've been told that if I converted to a 5 speed, my RPM's would be too low in 5th gear and it wouldn't be worth it...

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2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999

diesel don,

First, there are two different ratio 4 speed transmissions. We have the higher first gear one in a 300DT with a 3.07 rear end and it's a little reluctant to start moving on a very steep hill. I have the lower ratio in my 240D/300 with a 3.07 rear end ratio and can out accelerate the turbo in first gear. I can also start much easier on a steep hill.

Do not, and I mean do not put the 2.88 rear end in as you'll won't like the results. Your highway mileage will be great but it gets very breathless on hills. I walked a freind through installing a manual 4 speed in his '85 wagon and the results are as above. By the way, the friend was 71 at the time and had his broken leg in a plaster cast. Some people just won't quit!

Ideally, the best rear end for such a conversion would be the 3.27 out of a 124, but I'm told the swap won't work. With the 3.27 you'd get great off the mark movement.

Check the Haynes 280CE where you'll find all the ratios for trannies , five speed included.

Ben

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