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95 850 Help! Are these two transmissions swappable?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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850TurboTurtle
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95 850 Help! Are these two transmissions swappable?

Post by 850TurboTurtle »

The cars are both 95 turbo 850s. The donor car seems to have a smaller turbo unit, and a little different engine mounts and ABS system. I notice the 'new' 95J transmission has a sensor just to the right of the info tag, a speedo sensor? which the other dead tranny doesn't have. Am I doomed or can this work??

I'd love to know before I put in new seals and drop in the donor tranny.

Original (dead) tranny from 2/95 keeper vehicle: 50-42LE 94L
dead tranny from 2-95 vehicle
dead tranny from 2-95 vehicle
Donor tranny from 12/95 donor vehicle: 50-42LE 95J 1208-840
Donor tranny 95J
Donor tranny 95J

VIN and info on keeper car (2/95)
2/95 keeper car
2/95 keeper car
VIN and info on donor car (12/95)
12/95 donor car info
12/95 donor car info

Ozark Lee
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Post by Ozark Lee »

The donor car is a '96 model. The speed sensor on the '96 is not on the transmission like it is on the '95 which leads to some issues but they may be surmountable. I think you can tap a wheel sensor to get the VSS signal. There may also be a difference on the RPM speed sensor(s). If I'm not mistaken there are two sensors on the '96 (before and after the torque converter) but only one on the '95 which is the actual RPM sensor. I think you can just ignore the second sensor.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

tryingbe
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Post by tryingbe »

My 94 Turbo 850 have a 97 auto trans which does not have a speed sensor. I spliced the speed sensor signal from the driver side front ABS system, works fine. Leave the speed sensor on the trans be unplugged.
85 GLH, 367 whp
00 Insight, 72 mpg

850TurboTurtle
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Post by 850TurboTurtle »

tryingbe wrote: I spliced the speed sensor signal from the driver side front ABS system, works fine. Leave the speed sensor on the trans be unplugged.
So do you just wire from the wheel ABS sensor to some other spot on the car wiring harness? The donor tranny has a speedo sensor on the housing near the stamped tag, but the old dead tranny does not appear to have any speedo sensor on it.

Thanks for any details on how you do this! Very encouraging news.

(I edited this reply, because I had my tranny models confused for a sec. The older dead tranny is the one without the plug on the tranny housing.)

850TurboTurtle
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Post by 850TurboTurtle »

Ozark Lee wrote:I think you can tap a wheel sensor to get the VSS signal.
Lee, Any idea where the tap from the wheel sensor should go from there? I can figure out how to tap the wheel sensor, but where do I send the signal from there? I don't know where on the 95 model to patch in the wires.

Also, the donor tranny does have the speed sensor on the transmission housing, and the target vehicle does not. So don't I have one too many speed sensors somehow now?

And if the previous (now dead) tranny doesn't have a sensor on the housing, then where was the target vehicle getting its speed sensor data in the first place?

Thanks! Rick

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erikv11
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Post by erikv11 »

It sure sounds like you may have the transmissions mixed up.

The 94-95 models have a speed sensor at the back of the trans, and a plug in the wiring harness for it. Your 95 should have a speed sensor.

All 96+ get the speedo signal from ABS sensor, usually there is no plug in the wiring harness but I am not certain for a late 95 or early 96.

If you don't have them mixed up and your 95 truly has no speed sensor: Just drop in the donor transmission and don't worry about it, you will still be getting speedo signal from the ABS as you were before. Leave speed sensor unplugged on the new trans.

If you do have them mixed up and your 95 has a speed sensor: Find the wires that connect to your current speed sensor connector plug, and splice them into the ABS sensor wires. Then install the new trans.

I've never done this but it is a well tried and true solution, commonly used for like 10 years. First worked out by people swapping in newer transmissions but also a standard practice with most manual swaps.
'95 854 T-5R, Motronic 4.4, 185k
'98 V70, T5 tune-injectors-turbo, LPT engine, 304k, daily driver
'06 S60 R, 197k
'07 XC70, black, 205k
'07 XC70, willow green, 212k
'99 Camry V6 :shock: 153k
gone: '96 NA 850 210k, '98 NA V70 182k, '98 S70 NA 225k, '96 855 NA 169k

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Post by Ozark Lee »

Be careful here. If the donor is a '95 and the target is a '96 you will have problems since the second RPM sensor isn't there on the '95 transmission but the TCU expects to see a signal from it.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

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erikv11
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Post by erikv11 »

Does a TCU swap fix that, drop the 96 unit into the 95?
'95 854 T-5R, Motronic 4.4, 185k
'98 V70, T5 tune-injectors-turbo, LPT engine, 304k, daily driver
'06 S60 R, 197k
'07 XC70, black, 205k
'07 XC70, willow green, 212k
'99 Camry V6 :shock: 153k
gone: '96 NA 850 210k, '98 NA V70 182k, '98 S70 NA 225k, '96 855 NA 169k

850TurboTurtle
Posts: 279
Joined: 2 August 2011
Year and Model: 96 850T, 05 S80T6
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Post by 850TurboTurtle »

Ozark Lee wrote:Be careful here. If the donor is a '95 and the target is a '96 you will have problems since the second RPM sensor isn't there on the '95 transmission but the TCU expects to see a signal from it.

...Lee
Thanks Erik and Lee for the great input.

The donor is mfg in 12/95 as a 96 model according to VIN. The target is a 2/95 mfg and a 95 model year.

I think I have my sensors mixed up more than anything. On the dead 95 tranny there is a wide rectangular plug area beside the pax side axle hole. No such thing on the 96 donor. On the 96 donor there is a 1/2" round sensor on the top of the tranny just a few inches back of the stamped tranny info plate. Photos:

rectangle sensor on dead 95
rectangle sensor on dead 95.jpg

round sensor on donor 96
round sensor on donor 96.jpg

Ozark Lee
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Post by Ozark Lee »

erikv11 wrote:Does a TCU swap fix that?
It might. Both cars should have had a Motronic 4.3 ECU so it should be able to talk to either TCU. I've never tried it.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

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