Will a AT from '82 240D work in '81 300D? - PeachParts Mercedes-Benz Forum

davidhoward · #1 06-26-2006, 01:18 AM

I have a '81 300D that has a failing AT. It is not rebuildable because the cylinder wall of the B2 piston has a nasty groove worn in it, and when hot leaks so bad that it slips terribly.

I have found a deal on a '82 240D tranny (car was hit from the rear and totalled). I'm sure both AT's are of the 722.x family, but the question is will the '82 240D AT bolt up to the '81 300D (same bell housing? same length? same linkage?)

David

Samuel M. Ross · #2 06-27-2006, 10:16 PM

I have a 1980 240D and 300D... the first with a 722.117 and the latter with 1 722.118 tranny. Unless these cars have different differential gear ratios, I think the trannies have different gear ratios to allowing for the 20-25% difference in horsepower! Another thought is that the 300 has different size tires but I don't think that would be the way they designed for the different engines.

Go slow and be certain before you buy!

Sam

Samuel M. Ross · #3 06-27-2006, 10:27 PM

I see that specifically:
the 79-85 240D's engines developed 72 h.p., and
the 79-85 300D's engines deveolped 88 h.p.

Just for your reference!

I have not pinned down the exact tranny numbers but I think my
722.117 -vs - 722.118 is correct.

Sam

davidhoward · #4 06-29-2006, 12:23 AM

My tranny is a 722.118 4 bolt

Samuel M. Ross · #5 06-29-2006, 01:13 AM

result in the engine noticeably reving higher RPMs than you are normally accustomed to... and at the top end this will mean that on over-the-road trips you will not get as good a fuel mileage as you have in the past.

The prediction above presumes that you make no change in the rear-end gear ratio. I might be possible for you to make changes in your differential that would off-set [normalize] whatever miss-match the exchange might cause.

It just dawned on me to ask... when you say " My tranny is a 722.118 4 bolt "... is this the one coming from the 240D? Well according to my Official 1980 MBZ Model 123 chassis Catalog, a tranny with this number has the exact same starting numbers as the one in my 300D... which has the following complete number/sn: 1232703201 722.118.02.098161 .

So if you are saying that your potential new/used 722.118 tranny that is coming from the 240D, then there is a definite possibility that it was originally in a 300D model when it came from the factory... and now it could be that you are once again matching it up with it's rightful power plant !
Regards,
Sam

davidhoward · #6 06-30-2006, 12:38 AM

In my 81 300D the tranny is a 722.118 --- I have the ATSG book for 722.1, 2 which says it covers the 1968-1981 four bolt pan model transmissions 025,040,050. According to this manual, the gear ratios are 1st 3.98, 2nd 2.39, 3rd 1.46, 4th 1, Reverse 5.47. There are no differences in ratios of any of the 722.1,2 transmissions. The torque converter is the only difference between 240D and 300D I've seen in the ATSG manual. The 240D (model 123.123) is 1500-1700 RPM stall, and 300D (model 123.130) is 1600-1800.

The problem is, I believe the '82 240D might be a 722.3 transmission for which I do not have a manual (yet). It there a guide somewhere as to what the tranny number for an '82 240D (US) would have?

#7 06-30-2006, 01:05 AM

Does this help?

http://www.adsitco.com/category.asp?CID=1644

Samuel M. Ross · #8 06-30-2006, 01:21 AM

by using the following to search on: 1982 240D mercedes transmission
I found the following WebPage:
http://www.transmissioncenter.net/VehicleTransmissionIndex.htm#MERCEDES
which says that all 240Ds from 1974 to 1983 had the 722.1 tranny. The 722.3 trannies that early were in the 300 models. Strange however that this same WebPage does not show nearly all of the diesel models!?
I hope this helps
Sam

Samuel M. Ross · #9 06-30-2006, 01:29 AM

by giving you the full p/n(s) and other tranny numbers that are usually stamped into the body of the transmission on the side just above the pan.

E.g. as I posted earlier my 722.118 numbers are:
" 1232703201 722.118.02.098161 "

Sam

Pete Burton · #10 06-30-2006, 08:43 AM

FWIW, I'm 99% certain the trans from the 240D will bolt up. It probably makes the most sense to bolt up a good used unit. There may be a few differences in the unit's shifting characteristics which are controlled by the valve body, but you can just swap over the valve body from the 300D trans.