760 GLE Turbo Diesel trans swap

Hi guys,
I have been on the hunt for a 240 for the last few months and coincidentally stumbled into a 1985 760 GLE TD an old lady has. It's incredibly clean but the car was parked 3 years ago due to a "blown transmission". I looked it over thoroughly and there is not a spot of rust to be found, and the interior is pretty much mint. All of the service records are there, and the odometer reads 128k miles. They didn't even put the car in park when they had it dropped off at their house the shop- it was still in neutral. The owner and I came to a consensus that the car is worth about $500 with the clean title and both keys.

In light of this "blown transmission", is it possilbe for me to swap in one of two transmissions:
1. A newer 240's A71 slushbox- yes this would be "original"
2. A 5 speed manual (M47) because it's a diesel and I need every performance advantage I can get

I really want to put in a manual transmission, given the fact that the current one is shot. How hard will it be for me to find a diesel flywheel and 740/760 manual parts? Can I use some 240 parts, or does everything (except the physical transmission) have to come from a 7xx car?

James

To answer your questions 1 & 2, connecting those transmissions is not really possible as the D24T has a different bellhousing mounting pattern than what those transmissions have. The ZF HP22L (what it probably came with stock) is really the best performing for that setup. Good performance (best performing diesel of its time period), good driveability. The other option was the M46 (again, with special bellhousing) which is really no better for performance, but can deliver better mileage.

The ZF HP22L had a failure mode that would burn the friction disks if the engine was revved while in P or N, after having engaged D or R. So an emissions test would easily burn up the tranny. This was later addressed in later TSBs with improved parts.

In that case, where is the best place to find a good used or rebuilt ZF HP22L?

Am I able to use a ZF HP22L from a BMW or other european make?

Not sure where you're located, but I've got an M46 setup from a 760. Another option would be a T5 conversion, but I don't see a real need for that at stock power levels.

Wren said:

Not sure where you're located, but I've got an M46 setup from a 760. Another option would be a T5 conversion, but I don't see a real need for that at stock power levels.

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Would a T-5 fit the diesel belllhousing bolt pattern?

Wren, I am located in Kingsville MD. Do you have the bell housing for a diesel? Can you send me a PM- I'll buy it.
James

Diesel M46/M47 bellhousing has a different bolt pattern to a Redblock, obviously. However, as bellhousing is removable on those, with a diesel bellhousing you can swap an M46/47 from a petrol car. Obviously, if T-5 adapter takes entire M4x bellhousing, then you can bolt a diesell bell to it.

I wouldn't bother. M46 or even "the weak" M47 would work with D24T for ages. D24's tend to suck though.

Check things out before you plan any swaps... old ladies arent the best at transmission diagnosis. Maybe it just needs fluid or something else easy.

arsenix said:

Check things out before you plan any swaps... old ladies aren't the best at transmission diagnosis. Maybe it just needs fluid or something else easy.

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They had it towed to their local Volvo dealer where they diagnosed the bad transmission. My plan is to first make it run and then play with the trans to see what life it still has (if any). Maybe I'll get lucky and be able to revive it with some Trans-X. The car was still in neutral from when they towed it 3 years ago.

I think the m46/47 should be more than enough for the swap, assuming I can find a bellhousing . I don't plan on making this a tire burner and am fully aware of the shortcomings of the D24T- this is going to be a comfortable daily driver (read: road couch).

James

Do I need a different flywheel too? One that is unique to just manual D24's, or is the flywheel that is currently attached to the torque converter workable for a manual transmission (ie just bolt a clutch and pressure plate on)?

Is there a difference between the actual diesel m46 trans and a gas m46? I understand the bh and Shift linkage is different, but is the input shaft different too?

The input shaft is the same except for a bushing that pressed on the end. The bushing is NLA, but Skandix was kind enough to take measurements so you can make your own.

I was able to order that bushing from volvo last summer even though they said it was NLA, came from germany only took a week.

vwbusman66 said:

Is there a difference between the actual diesel m46 trans and a gas m46? I understand the bh and Shift linkage is different, but is the input shaft different too?

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Not sure if the shift linkage is different, but the the turbo diesel application has a higher-pressure OD Pressure Relief Valve. Probably stronger spring, thicker shims, or both. The engineers may have been thinking it needed higher pressure to keep the OD clutch from slipping under the higher torque load. Not sure it really makes a difference.

Flywheel definitely different-- different bolt pattern, dog dish style. Therefore requires clutch disk and pressure plate to match, so throwout brg. probably different also. Cable operated fork.

Input shaft bushing (the one that is in the end of the crankshaft) much different.