86s spare auto transmission - refurb?
11-21-2017, 03:10 PM
#1
Intermediate
Thread Starter
86s spare auto transmission - refurb?
Hello from the Twin Cities! First time poster. I have a 1986 928s with an upcoming need for TT and/or TC bearing replacement (noisy). My question is this - I have a complete spare transmission sitting on the floor. I'm thinking of either partially or fully overhauling the spare tranny for peace mind and reduced r&r time for the TT job. The spare has 90k on it & knocking on 200k with original in the car. To what extent should I overhaul this spare unit prior to swap? No known issues with it going in.
Thanks
Scott
Thanks
Scott
11-21-2017, 04:07 PM
#2
Vegas, Baby!
Rennlist Member
Rennlist Member
I did a tranny swap with my 89, and it's year specific. Got a used one from Los Angeles Dismantler. Changed the B2 springs with a kit from Roger, along with the filter and gasket new fluid in the tranny and deferential. Didn't really know the mileage, but so far it's works great. When I have time, I'll give the original trans to Greg Brown, for a complete rebuild, and replace the TT, with a rebuilt from Black Sea R&D.
Since your spare has no known issues, I'd swap it out, and have Greg Brown rebuild it. Keep it as a spare, or do another swap, and sell the spare. I have a lift, with a 3 stage transmission jack, so It's not that big a deal for me to change out the trans in my car. My car is supercharged, so I want a unit that's had Greg's magic applied to it!
Since your spare has no known issues, I'd swap it out, and have Greg Brown rebuild it. Keep it as a spare, or do another swap, and sell the spare. I have a lift, with a 3 stage transmission jack, so It's not that big a deal for me to change out the trans in my car. My car is supercharged, so I want a unit that's had Greg's magic applied to it!
11-21-2017, 07:11 PM
#3
Chronic Tool Dropper
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Reinforcing Joe's recommendation:
The M-B trans in the 928 isn't something you would drop off at the local AAmco, then put aside for later. There are some know concerns with rebuilding them, particularly about using knock-off replacement parts and getting the assembly just right the first time. Some searching here will net you some success stories but more horror stories. Maybe only bad news travels to the forum here, but still I'm not quite ready to hand off the box to Hank the Handyman for specialized work. Greg isn't cheap, but I know that it will be darn close to perfect when he's done.
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I love my 1989 with the 2.54 gears and the closer trans ratios. It's noticeably livelier than the 2.20 boxes from prior years. No such thing as a free lunch though. There are more times now when having the ~~15% lower final drive would make "touring" a little more pleasant. We moved from the big city to the wider-open spaces and don't really need the 2.54 performance so much now. A SoCal 'lister was parting his '88 recently, and the 2.20 box and torque tube moved closer to my car. I'll rebuild and install the torque tube for sure. Meanwhile, the original '89 box drives perfectly. Should I spend to refresh the '88 before I put it in (reported to be fine coming from the car), or spend on refreshing the original '89 box before mothballing it to stay with the car as a rebuilt spare? It's pretty much the same dilemma you face. I'll probably put the question to the high priest himself before deciding.
The M-B trans in the 928 isn't something you would drop off at the local AAmco, then put aside for later. There are some know concerns with rebuilding them, particularly about using knock-off replacement parts and getting the assembly just right the first time. Some searching here will net you some success stories but more horror stories. Maybe only bad news travels to the forum here, but still I'm not quite ready to hand off the box to Hank the Handyman for specialized work. Greg isn't cheap, but I know that it will be darn close to perfect when he's done.
---
I love my 1989 with the 2.54 gears and the closer trans ratios. It's noticeably livelier than the 2.20 boxes from prior years. No such thing as a free lunch though. There are more times now when having the ~~15% lower final drive would make "touring" a little more pleasant. We moved from the big city to the wider-open spaces and don't really need the 2.54 performance so much now. A SoCal 'lister was parting his '88 recently, and the 2.20 box and torque tube moved closer to my car. I'll rebuild and install the torque tube for sure. Meanwhile, the original '89 box drives perfectly. Should I spend to refresh the '88 before I put it in (reported to be fine coming from the car), or spend on refreshing the original '89 box before mothballing it to stay with the car as a rebuilt spare? It's pretty much the same dilemma you face. I'll probably put the question to the high priest himself before deciding.