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By JBRob007
#67845
Sharks,

Will a 4 speed AUTO transmission (85 model year) fit as a replacement for a 3 speed AUTO transmission (82 model year)? If so, are there any adjustments required such as a new torque tube, drive shaft, 1/2 shafts, tranny mounts, etc...?

Inquiring minds wanna know! Thanks!!!
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By maddog2020
#67945
torque tube is different for the 4 speed, and if I recall the trans harness is different as well. not sure about the shifter and linkage. I did a swap about 15 years ago.
By JBRob007
#69050
Hmmm... Much more of a heavy lift than I had been lead to believe. I have my sights on a 4 speed tranny, but it does not come with the torque tube so that's a non-starter :(
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By Geza-aka-Zombo
#69201
Perhaps I'm wrong, but I was under the impression that the 4 speed is larger and wouldn't fit in the tunnel of the earlier 3 speed cars? Modifications required, maybe?
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By Landseer
#69253
Sounds like a length difference.

I've installed 89 S4 auto into 84 OB.

That torque converter is at least an inch larger diameter. But no length diff.

But it fits, albeit tightly, into the OB shell.
Great answer to my particular situation of broken internals on original 4 speed. Broken parking pawl took out the case.

IIRC, I had a choice of old or new TT, picked old. Need to use S4 Bowden cable, modified to cut and remove part of the hard casing. The hookup to 84 throttle linkage bare wire, no end, so easy.

Maybe this will expand your possibilities for the earlier car
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By The Fat Man
#69341
Geza-aka-Zombo wrote: Fri Mar 26, 2021 9:46 am Perhaps I'm wrong, but I was under the impression that the 4 speed is larger and wouldn't fit in the tunnel of the earlier 3 speed cars? Modifications required, maybe?

Geza, pre-87 A28.** 4spd autos will fit with a little mallet massaging of the floor pan. Post-87 A28.** autos have a larger torque converter, and corresponding larger case at the front. Much bashing of the floor pan required. Not good.
Geza-aka-Zombo liked this
By JBRob007
#69353
Seth, you crazy Kraken drinking SOB... How you doing?!?!?! The earlier (pre-87) is what I’m looking to replace it with. So, other than swapping / modifying the cable to the WRONG side, will it bolt up? I know the later 1/2 shafts have end caps, but they SHOULD swap right out with a little BFH persuasion on the heat shields... correct?
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By Landseer
#69369
Seth, have you actually swapped them? I have and it worked fine. Granted I did whack the tunnel a half dozen times. And trans mounts probably wouldn't have met your standards...

Chalked the rest up to folklore. isnt the first time the prevailing fact was wrong. Like ljet controllers never go bad. Or tach bounce means CPS is good.
By JBRob007
#69370
You mean that shit's about the tach bounce is NOT TRUE!?!?! I've been soooooo misled... ;(
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By The Fat Man
#69393
Chris, I have not actually done this swap. I have only seen this info in my research. My experience is only with the A28.07 in my Red Witch.

Hi Joel!!! Still shoveling money into the Red Witch with no real progress. As life and other commitments keep getting in the way. Though I am still swilling Kraken in rusty shot glasses like I have no sense...

Joel, the swap is doable, however...I have to ask: why?

Back in 2015, I asked the same question. At the time, I only thought I would be able to afford an early 80's 928 with L-Jet and an A22.0* 3spd auto. Coming from the GM world, I learned to put a 4spd auto with OD in place of the existing 3spd autos. Worked a treat. In the 928 world...
First problem is top gear is still 1:1 for both transmissions. More importantly, the (relative) lack of low end torque of the early L-Jet engines meant the A22.0* had a pretty steep 1st gear. Folklore and TSTSNBM conventional wisdom says the A28.** will lug the L-Jet engine.

It is my understanding that a well tuned L-jet with a properly set up A22.0* 3spd auto is still quite fun to drive. Not 84 Twin Dizzy Euro 5spd fun (cough, cough), but fun nonetheless.
By JBRob007
#69463
Seth, I have a NEW TO ME 82 OB with 5.0 liter short block and 16V top end (cams & intake) that was built by 928 Motorsports specifically for a 928 MS Super Charger kit. We're bringing it back to stock (sans SC kit) and have been tweaking the tranny modulator as it was turned WAAAAAY left (probably to smooth it out the boost when it came on). So, the 3 speed tranny is probably O.K., but I was planning ahead in case it wasn't. As it turns out, the 3 speed tranny starts out in 1st and with a 5.0 liter under the hood it gets out of it's own way pretty quickly. I think we're good.

In other news, if you come to Amelia Island, the 928 Buckeye Landsharks are bringing our own BLS Bourbon Whiskey bottled and labeled by yours truly. It's 100 proof (so it has some kick) and it's GOOOOOOOD! Limited production BLS "Sharks Circling Amelia Island" label on only 40 bottles - We're caravaning down in about 5 cars and we'll probably bring 30 bottles to FL for sale to 928ers ONLY. I'll have a community bottle or two for "tastings" :beerchug: Hope to see you there :rockon:
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By worf
#69467
JBRob007 wrote: Sat Mar 27, 2021 2:57 pm In other news, if you come to Amelia Island, the 928 Buckeye Landsharks are bringing our own BLS Bourbon Whiskey bottled and labeled by yours truly. It's 100 proof (so it has some kick) and it's GOOOOOOOD! Limited production BLS "Sharks Circling Amelia Island" label on only 40 bottles - We're caravaning down in about 5 cars and we'll probably bring 30 bottles to FL for sale to 928ers ONLY. I'll have a community bottle or two for "tastings" :beerchug: Hope to see you there :rockon:
Yaw’ll gonna need to watch out for this guy:

Image
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By The Fat Man
#69468
Sweet! Did not realize you had a 5.0L hybrid engine. That will be something to have. Glad the 3spd worked out OK. I am assuming you are going to do a fluid and filter change, and make sure all the cables are set right?

Unfortunately, I will not be at Amelia. I don't have the vacation time. Sorry.
However...I would be interested in buying a bottle of 928 BL bourbon.
By JBRob007
#69477
If I can get a Sally Fields look-alike to be my navigator then it might be worth battling it out with the Sherriff and Junior ;) If we have any bourbon left over, I'll save you a bottle - Frankly, we'll probably do it again for Frenzy if this batch sells. Not looking to make a lot of $$ - mostly doing it for fun, make it a one of a kind bottle thing and adding to the club coffers for the Arthritis Foundation car show (Mike and I run the Porsche corral) with "refreshments" for club members.

We're going over the whole car as it was a barn find and I'll probably sell it on here after we're done. We removed the 928 MS Super Charger kit (BTW, it's for sale) and returning it to a stock intake. The paint is Chiffon White, all original, single stage which should buff out VERY nicely. The rub strips' paint (both) are peeling but the rest of the car will be a good 5-10 footer - straight, no dings, minor scratches. Most of our work will be cosmetic, interior, seat repairs & dye, carpets cleaning, paint touch up, correction and buff. The car already has many upgrades like steel sleeved cylinders, forged pistons, mini-starter, new engine wiring harness & green wire, injectors / injector hoses & new wires / connectors, a complete top end refresh, rebuilt 1/2 shafts, oil pan spacer w/ modified oil pick up, steering rack bushings and it's absolutely DRY underneath the engine... The auto tranny seeps a little (old seals) but nothing crazy. I've got orders in to Roger and Mark (928 Intl) for rebuilt fuel hoses (from Sean) and stock intake, fan, mounts, shrouds, airbox, tubes, etc, from International... Everything electrical WORKS which is surprising. It'll need a dash recover (not going THAT far), but everything else should be sorted. We like projects ya know :)

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