Help identifying my transmission - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Peanut74 · Today, 11:17 AM

This one has me stumped big time.
The transmission that came in my '67 appears to be a TH350. HOWEVER, it has only two speeds. The trans pan has the angled corner notch and 13 bolts indicating that it's a TH350 which is a three speed. Thought maybe it a TH250 but that's also a three speed from what I found. I may at a loss as to what it is. Any help in identifying it would be greatly appreciated.

**Stocker** · Today, 11:44 AM

Defective TH350 that fails to engage one of its three gear ratios?

Is there a transmission listed on the SPID?

**Ol Blue K20** · Today, 11:51 AM

Powerglide- 2 speed auto

**Getter-Done** · Today, 12:18 PM

Here's a link with info.

Sounds like there issue with the transmission not shifting.

Link: https://www.chevyhardcore.com/tech-s...uminum%20units

Peanut74 · Today, 02:02 PM

I went under the truck and shifted it manual and it is indeed a two speed. I went back underneath it looking for any markings on the transmission case. The only thing I found was 8T. There was no M33, M38 or M39 on it. Snapped a couple pictures hoping that would help.

Also, the guy I bought the truck from just had the transmission rebuilt.

**Stocker** · Today, 02:48 PM

I was not aware that a Powerglide was still used in some of these trucks. Does a Powerglide have the angled corner on the pan? Seems like I learn a bit more almost every day -- or learn how much I don't know.

Peanut, if you can talk with the shop that rebuilt the trans, they should be able to fill you in on all the details.

**Getter-Done** · Today, 03:00 PM

Maybe the guy that rebuilt it done a custom job.?

How long is that tailshaft?

That appears to be the T350 case.

There was a long and short tail shaft on the T350.
There was also a 12" tail shaft on some T350 cars.

The aluminum case powerglide had 14 bolts in the pan.

The Early Powerglide was Cast iron and IIRC it did not have a pan.

SRU1436 · Today, 03:04 PM

Look at the pans, they are different.

**Steeveedee** · Today, 03:47 PM

Sure looks like a 350 pan. How many notches in the detents of the shift selector? Six (PRND2L) would mean a three forward speeds (THM) and five (PRNDL) would mean two forward speeds (PG).

In the two gears, how fast do you go at what RPM?

As an afterthought, does it shift on time? If the vacuum modulator is weak it can shift way late or not at all, and you might not be getting high gear.

Today, 11:17 AM	#1
Peanut74 Registered User Join Date: May 2018 Location: Prattville, AL Posts: 597	Help identifying my transmission This one has me stumped big time. The transmission that came in my '67 appears to be a TH350. HOWEVER, it has only two speeds. The trans pan has the angled corner notch and 13 bolts indicating that it's a TH350 which is a three speed. Thought maybe it a TH250 but that's also a three speed from what I found. I may at a loss as to what it is. Any help in identifying it would be greatly appreciated. __________________ -------------------------------------------------------- 1967 C10 "Snowball" (Currently in a thousand pieces down from a bazillion) 1989 Toyota DLX pickup "The Hulk"

Today, 11:44 AM	#2
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,607	Re: Help identifying my transmission Defective TH350 that fails to engage one of its three gear ratios? Is there a transmission listed on the SPID? __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

Today, 11:51 AM	#3
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 16,060	Re: Help identifying my transmission Powerglide- 2 speed auto __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man

Today, 12:18 PM	#4
Getter-Done Senior Member Join Date: Dec 2009 Location: TN. Posts: 8,049	Re: Help identifying my transmission Here's a link with info. Sounds like there issue with the transmission not shifting. Link: https://www.chevyhardcore.com/tech-s...uminum%20units __________________ ________________________________________________________________________________________ ____________________________________________ 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build

Today, 02:02 PM	#5
Peanut74 Registered User Join Date: May 2018 Location: Prattville, AL Posts: 597	Re: Help identifying my transmission I went under the truck and shifted it manual and it is indeed a two speed. I went back underneath it looking for any markings on the transmission case. The only thing I found was 8T. There was no M33, M38 or M39 on it. Snapped a couple pictures hoping that would help. Also, the guy I bought the truck from just had the transmission rebuilt. Attached Images __________________ -------------------------------------------------------- 1967 C10 "Snowball" (Currently in a thousand pieces down from a bazillion) 1989 Toyota DLX pickup "The Hulk"

Today, 02:48 PM	#6
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,607	Re: Help identifying my transmission I was not aware that a Powerglide was still used in some of these trucks. Does a Powerglide have the angled corner on the pan? Seems like I learn a bit more almost every day -- or learn how much I don't know. Peanut, if you can talk with the shop that rebuilt the trans, they should be able to fill you in on all the details. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

Today, 03:00 PM	#7
Getter-Done Senior Member Join Date: Dec 2009 Location: TN. Posts: 8,049	Re: Help identifying my transmission Maybe the guy that rebuilt it done a custom job.? How long is that tailshaft? That appears to be the T350 case. There was a long and short tail shaft on the T350. There was also a 12" tail shaft on some T350 cars. The aluminum case powerglide had 14 bolts in the pan. The Early Powerglide was Cast iron and IIRC it did not have a pan. __________________ ________________________________________________________________________________________ ____________________________________________ 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build

Today, 03:04 PM	#8
SRU1436 Registered User Join Date: Mar 2019 Location: San Ramon, CA Posts: 223	Re: Help identifying my transmission Look at the pans, they are different. Attached Images

Today, 03:47 PM	#9
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,357	Re: Help identifying my transmission Sure looks like a 350 pan. How many notches in the detents of the shift selector? Six (PRND2L) would mean a three forward speeds (THM) and five (PRNDL) would mean two forward speeds (PG). In the two gears, how fast do you go at what RPM? As an afterthought, does it shift on time? If the vacuum modulator is weak it can shift way late or not at all, and you might not be getting high gear. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.