[Elco68]

I have been trying to identify the transmission on my 68 El Camino, and the site that I have been using to help me with identifying it (Which I got of off Hotrodders ) I'm not sure if its a THM350, a THM200, or a THM250, it seems to match the pan style of the 350, but the pan sketch I got for the 350 is a bit different from my actual transmission. Here's some terrible sketching I did:

This is for the way the 350 is supposed to look



This is mine



Does it matter that my transmission has the cut corner on the other side?

I also noticed there was a difference in the serial number (Which I found on the passenger side, on the pan)

The example serial number I got from the earlier stated site was C213N for a pre-67 and P9E03 for a post-67 example. I don't know if the year goes for the car it was built for, or the transmission itself, but the numbers I found on the side of my transmission were:

Y6M 15N

and there was a space like that too.

The transmission is also a 3-speed, although the car was originally powerglide.

Any help would be greatly appreciated, as I am very new to hot-rodding and haven't done anything major yet.

[tnsmith10]

it would really be an oddity to see a metric 200 in a 68 elcamino.
it could be a similar version of the th350 (god its been a long time) but i believe its a 275 in which u'll find a band adjustment nut located on the top passenger side of the case just before the bellhousing. both of the diagrams that would indicate the transmissions your showing both have the cut on the same side, but the metric 200 is a narrower case than the 350 and the pan also is more of rectangular design to where the 350 is a basic square with the corner cut off.
by chance does the bottom of the pan say metric on it? that would be a good indicator if the possibility of it being a metric 200. as far as i can remember, the metric 200 didnt come around till 75 or 76, and the early models did not come with a lockup torque converter ( i know, cause my 76 ventura from the factory came with a metric 200 and there was no connector on the drivers side of the case). hope this helps. if anything, take a pic and post it. it would help on telling at least what it is..

[joe_padavano]

Originally Posted by Elco68

I have been trying to identify the transmission on my 68 El Camino, and the site that I have been using to help me with identifying it (Which I got of off Hotrodders ) I'm not sure if its a THM350, a THM200, or a THM250, it seems to match the pan style of the 350, but the pan sketch I got for the 350 is a bit different from my actual transmission. Here's some terrible sketching I did:

This is for the way the 350 is supposed to look



This is mine



Does it matter that my transmission has the cut corner on the other side?

I also noticed there was a difference in the serial number (Which I found on the passenger side, on the pan)

The example serial number I got from the earlier stated site was C213N for a pre-67 and P9E03 for a post-67 example. I don't know if the year goes for the car it was built for, or the transmission itself, but the numbers I found on the side of my transmission were:

Y6M 15N

and there was a space like that too.

The transmission is also a 3-speed, although the car was originally powerglide.

Any help would be greatly appreciated, as I am very new to hot-rodding and haven't done anything major yet.

Well, the TH350 was not released by GM until the 1969 model year, so I'm not sure what the pre-67 reference is that you used above. Is the notch on the driver's side or passenger side? The TH350 and the TH200 both have the notch on the passenger side. The TH350 uses 13 bolts on the pan, the TH200 uses 11 bolts. These pictures are from the bottom looking up.



1 = Powerglide
2 = TH200
3 = TH350
4 = TH400
5 = TH200-4R
6 = 700R4
7 = 4L80E

[Elco68]

Okay thanks a ton guys I will take another look at it, no doubt that this helps

[mmerlinn]

It looks to me that you are looking at the pan from the bottom in your picture and from the top in your reference which is the normal way to look at pans.

Someone has put a different trans in your car at some time in the past. From your picture I would say you have a 350, but they never came in 1968s. If it is a 3 speed it is a 350, if a 2 speed then a 250. Pan is identical for both of them.

[Crosley]

Originally Posted by mmerlinn

It looks to me that you are looking at the pan from the bottom in your picture and from the top in your reference which is the normal way to look at pans.

Someone has put a different trans in your car at some time in the past. From your picture I would say you have a 350, but they never came in 1968s. If it is a 3 speed it is a 350, if a 2 speed then a 250. Pan is identical for both of them.

All of the t-250C trans I have seen are 3 speed trans with lock up torque converter.

A t-250C trans is usually ID'd by the thread band stud that sticks out of the case near the cooler line fittings.

[tnsmith10]

thanks for the correction crosley, its been a very long time since ive seen 1, and in all honesty, could not remember what they called it...

[matt69olds]

Greetings from Indiana! Maybe I can help. The th200 looks very simialar to a 250 and 350. It can be identified by its one peice case (non-removable extention housing) and the lack of a vaccum modulator. The th250 looks almost exactly like a 350 except for a band adjusting screw on the pass side of the case. The easiest way to i'd a lock-up vs nonlock-up is lock-up trans have a blue 4 pin connector on the side of the case. One peice case and no modulator=th200, band adjust screw,removable extention housing=250, addition of blue connector on pass side of case= lock-up. Hope that helps!

[Crosley]

Originally Posted by matt69olds

Greetings from Indiana! Maybe I can help. The th200 looks very simialar to a 250 and 350. It can be identified by its one peice case (non-removable extention housing) and the lack of a vaccum modulator. The th250 looks almost exactly like a 350 except for a band adjusting screw on the pass side of the case. The easiest way to i'd a lock-up vs nonlock-up is lock-up trans have a blue 4 pin connector on the side of the case. One peice case and no modulator=th200, band adjust screw,removable extention housing=250, addition of blue connector on pass side of case= lock-up. Hope that helps!

the t-350C and t-250C electrical connector for lock up was on the drivers side near the shift linkage. I have seen a square 4 hole connector or a 2 hole, oblong shaped connector.

[mmerlinn]

Originally Posted by Crosley

All of the t-250C trans I have seen are 3 speed trans with lock up torque converter.

A t-250C trans is usually ID'd by the thread band stud that sticks out of the case near the cooler line fittings.

The TH250 & TH250C do not have a sprag on the back of the direct drum whereas the TH350, TH350C, & TH375B do. Also, there is no clutch piston on the stator support on the 250s whilst there is on the 350s & 375B. To the best of my knowledge the lack of those items makes the 250s 2-speeds whilst the 350s & 375B are 3-speeds.

And you are correct. The ONLY easy way (short of comparing casting numbers) of telling the 250s from the 350s/375B is the band adjusting screw for the front band. And the easy ways to determine the lockups (250C & 350C) from the non-lockups (250, 350, & 375B) is by the wire plug on side of case or the polished tip on input shaft.

[SSedan64]

TH-250
A light duty 3 speed version of the TH-350 tranny. The TH-250 and TH-350 are almost identical, except the TH-250 uses an intermediate band for all 2nd gear applications where the TH-350 uses intermediate clutch for automatic 2nd gear and the intermediate band for manual 2nd gear.

From a GM manual.