If anyone can help I would be greatful. I need help decoding my transmission to see if it is for a v6 or v8 engine. I took out a T5 manual and 305 tbi and swapping in a 350 carb and I bought a 700r4 from someone that said it was behind a v8, anyway here is the numbers 14TM151C, MD8, and 8663549. I think the first number means that is 1991 built 151 day of the year at night shift, the second number just means it's 4l60 or 700r4 having trouble with third number,please help someone.

 

Just snap a picture of the bellhousing, that's the fastest way of knowing.

 

What he said. They look very different.

 

if the bellhousing is about 18" across, then it's a V8 trans... if it's closer to a foot across, then it's a V6..

 

V6 bellhousing is more of a trapezoidal shape.

 

http://en.wikipedia.org/wiki/List_of_GM_bellhousing_patterns

 

Here is a pic of bellhousing

 

V8

 

Yep, V8.

 

Thank you all for the help that was a relief.

 

It could have come behind a 4.3L V6...

 

If it was for a 4.3 v6 could you rebuild it like a v8 and have the same internals in it?

 

I dont see why not. The guts on a 60* V6 700r4 are almost all exactly the same.

 

Thanks for all the help everyone god bless.

 

Does it have the Fbody tailshaft?

 

Will have to send a pic tomorrow.

 

here are some pisc of tailshaft not sure about the different sizes of them. If someone can tell me if this is a fbody tailshaft.

 

Of course. Valve body calibration (shift points) are most likely different compared to the V8. Clutch stack ups might be different as well.

 

Its a f body tailshaft and v6 and v8 the internals are the same

 

usually there's one less friction disc in each clutch pack if it's a v-6, to make it a v-8 you have to change the piston in that drum (to make it shorter) so you can add another friction and steel in that clutch pack.

if you are making more power than stock, I would suggest making it like a v-8.

trans by your code would be a '91 4TM. I am trying to find out what it was in.

are you POSITIVE it is a '4' TM -- an FTM they are telling me is out of firebird or camaro 5.0 -- they don't show a 4TM.....

 

The internal s are the same v6 or v8 look up rebuild kit it the same.

 

The servo, boost valve, and intermet. valve are different. Smaller. At least this is true with 60* 700r4's

I know this because of adding in a shift kit and relizing that every part was too tiny for a trans go's reprograming kit.

 

yes the kits are the same, but you have left over parts for the v6. I have overhauled hundreds of these, the 6's are different than the 8's.

 

My bad, yeah it is a f and not a 4. Thanks it was really dirty and I looked at it wrong

 

This is the best website to do anything with your third gen fbody, because it has the best people, so many bright minds. Can't thank you all enough.

 

SCORE !!! an f body trans for an f body car !!!

 

Yep, not a V6 trans of any kind.


I'd upgrade a few things while you have it out, It's not that bad to do on your own.


I'm putting about 350 HP/300TQ to a V6 700R4, spinning it to 7K RPM and it's taking it like a champ with the street/strip kit from Pro Built Automatics and a 4500 stall.

https://www.700r4l60e.com/store/prod...&cat=52&page=1

 

Mines good to go also with the trans go reprogramming kit, vette servo, larger intermediate and boost valve from probuilt. Id bet im right there with deathstar pushing 300+hp and more then that on Tq on a 3k stall up to 6500 rpms. And the ole 700r works fine.

Just read up and be patient. It was my first time working on the trans department and it was flustrating at times.

 

http://www.700r4l60e.com/forum/viewtopic.php?f=6&t=108

 

i was going to say when i was building my v6 transmissions to live behind my turbocharged 3.1 that i never had any leftover parts

i used the tci master race rebuild kits on mine

 

I didnt have left over parts, just parts that the insturctions said dont use. So I had to buy different parts so that I had ones that were "ok' to use with the kit.

 

that link talks about an "E" transmission.....

I've spent 17 years in a GM dealership building transmissions, I can't count the number of v-6 trannies that have one less clutch in each drum, and I have the stacks of extra clutches to prove it. I also cannot count the number of pistons I have changed to convert v-6 to v-8.

it's really no big deal...

 

LOL -- so they really weren't 'left over'?

 

It would be my first rebuild on my own. I've helped and watched someone rebuild a 700r4 but just back to stock specs. I haven't decided if I want to tackle it by myself or not yet.

 

Before I can even think about rebuilding the transmission got to rebuild my 350 carb engine.

 

greg, it would be cool to have a list of what the 3 letter code corresponds to what car it came out of. I know YMD is Corvette, and that's about it. Can you share your list (if you have one)?

And yes the F-body valve body is one of the better performance ones. My '89 Caprice cop car had an almost identical VB to what came out of the F-body's. Shift valves stamped: M (1-2), 10 (2-3), 0 (3-4)

 

I prodded a friend at the dealer to dig up some stuff.... I had a small list (like only a couple years) once upon a time, but seem to have misplaced it, sorry. If it turns up, I will post it.

I know a couple by memory from my dealership days: TAD is a baby blazer (but 4L60E)
and a KCD is a full size truck (4L60E)

 

I've taught a couple of people, not too awful difficult, just like a puzzle that you can't leave any parts out of--- neat part is, you get to start with the puzzle already assembled, and take it apart ....

 

Would be cool if someone kept a running list of known codes... But as long as you know what shift valves to look for you can easily locate the right valve body from a used parts supplier.

I come from a pretty broad mechanical background (cars, helicopters and now elevators), but was very satisfying (and frustrating at times) rebuilding my 700R4 and having it work (so far). Learning curve was pretty steep having only changed filters, fluid, and a few TV cables and lockup solenoids in the past. Very rewarding and would have no problem rebuilding another automatic in the future.