I'm having a tough time identifying the OEM transmission in my 90 RS V6. Some places it seems to indicate a THM200-R4 others says its a THM700-R4.

Can anyone point me to an accurate reference.

Thanks!

-Gerry
96 Impala SS
90 Camaro RS

 

I beleive it's the 700R4, same as the V8s, but don't quote me on that. I'm sure the guts of it are not as heavy-duty as the V8 version, even if it is the same type of trans.

 

As far as I remember, the 200 was phased out in the early 80's... like 84 or so I believe. The 700R4 was the tranny of choice for GM after that.

 

Hmmm... well this thing feels like it has a lockup torque convertor in it, and I thought the 700-R4 didn't have a lock up. The 200-R4 does though. The GM info I've looked at says the 200-R4 was used up till 89, but I can't find anything concrete about the 700-R4.

 

It is a 700R4.

 

believe in probuilt its a 700r4, i went through the same crap, a shop actually put the wrong filter in mine somehow, i changed it as soon as i found out, however, less than 6 months later, the trans went out, so we decided to convert the car to v8 since i had all the parts collected

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84' Firebird, 305ci lg4, 700R4, 288/292 duration .450/.460 lift,Edelbrock Performer intake, Holley 600cfm 4 barrel, K&N filter, Pacesetter Headers, 3'single exhuast, dual out muffler, no cat,Motive 3.73's and Auburn Posi
1/4mile 15.17sec @ 92.5mph

currently in pieces, for manual swap

 

I know that 200-4R were used up to 1990 in some of the larger station wagons, so bolt up to the last of the BOP engines (yes, 1990 was the last year for the 307), but thats NOT in an F-body. The only F-body to use the 200-4R was the 1989 Turbo Trans Am. The only automatic that was available in 1990 was the 700. By 1990 or '91, most of the internals were identical between the V8's 700 and the V6's.

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Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77

 

I had the exact same car with the exact same problem. I blew the trans at 90,000 miles. The guy who rebuilt said it was definitely a 700R4, and it was a 4 speed with lock-up torque converter. It ran beautiful until I got rid of it with 150,000 miles. I actually miss that car.

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2000 Camaro Z28 Monterey Maroon Metallic, auto,leather, 323 posi, Monsoon w/CD, T-tops

 

Thanks for all the good info. Having a 700R4 in there makes it a great candidate for swapping to a 5.7. I'm still on an uphill learning curver for f-body specs. Thanks again all!

-gerry

 

don't get too excited about being able to just change engines, becuz, the v6 and v8 have different, bellhousing shapes, and since the bell housing is a part of the case, you have to find another whole transmission

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84' Firebird, 305ci lg4, 700R4, 288/292 duration .450/.460 lift,Edelbrock Performer intake, Holley 600cfm 4 barrel, K&N filter, Pacesetter Headers, 3'single exhuast, dual out muffler, no cat,Motive 3.73's and Auburn Posi
1/4mile 15.17sec @ 92.5mph

currently in pieces, for manual swap

 

Well looking at the RPO codes this 90 RS V6 has a MD8 ( HM-4L60 ) and MX0 ( 4 speed ). In my factory service manual the chapter is labeled "4L60 formerly 700R4".

Guess this sort of clears it up.

-gerry

 

im positive its a 700R4

 

It's a 4L60. No Ifs, Ands, or Buts about it. But... the 4L60 is 100% identical to the 700R4. They just changed the name in 1990 to match up with the naming system of the rest of their transmissions. Starting in 94 the cars came with the 4L60E which is the electronically controlled version of the 700R4/4L60.

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The IROC Homepage
View the Restoration of an 85 IROC
Weekend projects aren't.

 

Yeah, GM played the "name game" back in 1990.

700R-4 -> 4L60
THM 400 -> 3L80
etc...

As with what firechicken was saying, just because its a 700, doesn't mean that you can yank the V6 for a V8. The V6 transmission has a 60° bellhousing, and the V8 and larger v6s (4.3L, not in an f-body) had the 90° bellhousing. You will need the 90° to bolt up to the V8.

------------------
Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77