66 Starfire trans
Thread Starter
Moosedrool
Joined: Oct 2011
Posts: 64
From: Minnesota
66 Starfire trans
I'm new to the Olds 425 configuration. What transmission do I have behind my '66 Starfire 425? I need to order the typical kit for trans fluid replacement and don't know what kit to order or where to find it. Thanks for giving me some feedback!!
Registered User
Joined: Mar 2007
Posts: 97
From: Omaha, NE
The transmission in the 1966 Oldsmobile Starfire (assuming that it's an automatic transmission and that it hasn't been swapped out in the intervening 45 years) is a Turbo-Hydramatic 400, commonly abbreviated TH-400 or THM-400.
As an owner of a full-size '66 Olds, you're in luck. GM used that same transmission in a lot of cars and (mostly) trucks over the decades, so parts are readily available and transmission rebuilders should be familiar with the unit.
You can get more info on the transmission here. Just scroll down about 5 pages, past the tables and descriptions of other models.
The early versions of the THM-400 used a special switch-pitch torque converter, with which you might want to familiarize yourself. See here.
If you are new to the Starfire, I have one piece of advice:
If you are having problems finding parts for the car, or if repair shops say they can't find parts for it, then tell them that the car is a Delta 88. Those 2 models share at least 95% of the same components, but the Starfire was rare enough that it just doesn't register in some parts databases. To pick a random example -- master brake cylinder. Doesn't show up in parts databases under the Starfire. But look for a Delta 88, and half a dozen appear.
As an owner of a full-size '66 Olds, you're in luck. GM used that same transmission in a lot of cars and (mostly) trucks over the decades, so parts are readily available and transmission rebuilders should be familiar with the unit.
You can get more info on the transmission here. Just scroll down about 5 pages, past the tables and descriptions of other models.
The early versions of the THM-400 used a special switch-pitch torque converter, with which you might want to familiarize yourself. See here.
If you are new to the Starfire, I have one piece of advice:
If you are having problems finding parts for the car, or if repair shops say they can't find parts for it, then tell them that the car is a Delta 88. Those 2 models share at least 95% of the same components, but the Starfire was rare enough that it just doesn't register in some parts databases. To pick a random example -- master brake cylinder. Doesn't show up in parts databases under the Starfire. But look for a Delta 88, and half a dozen appear.
Last edited by Mister; Oct 26, 2011 at 08:12 AM.
Thread Starter
Moosedrool
Joined: Oct 2011
Posts: 64
From: Minnesota
Thank you! I'm glad its a T400, I recognize that parts are available, and I've also heard that they are a strong and dependable transmission. I also appreciate the tip about looking for Delta 88 parts. Good advice and I'll use it.
Thread Starter
Moosedrool
Joined: Oct 2011
Posts: 64
From: Minnesota
Actually I have another question about the 425 big block. I need to replace the engine pan and my hunt will be easier if there are other GM pans that will bolt up to the 425. Is my pan unique, or do I have options????? Many thanks for any feedback!
Certifiable car addict...
Joined: Apr 2011
Posts: 392
From: SW Ohio
Sorry you never got a timely response on this, but here's the skinny as I know it.
The Olds 425 will only easily take a Big Block Olds (400/425/455) oil pan. Anything else may have to be modified (probably a lot) in order to bolt on the engine.
The 65/66 Starfire is a B-body chassis, and as such has the steering linkage behind the engine crossmember, which makes the clearance different than the 68 & up cars, and had a fairly unique pan.
So, to answer your original question...
For ease of installation, and a minimum amount of hassle, you want to get a 65/66/67 oil pan off a B-body, big block engine. That will be a direct bolt in with no clearance issues.
I remember back when I rebuilt the engine on my original starfire (in 90-91 or thereabouts), while it was out, we tried to test fit an Olds 455, Buick 455, and a Pontiac 400 in the engine bay, just because we had them lying around at the time and wanted to see if one would bolt in to get me up and running for a while to play with while the original engine was being built.
None of them would fit for various reasons, and even the newer Olds 455 oil pan would not clear correctly from where the steering & engine crossmember were on that chassis.
I think I'm right on this info, but please correct me if I'm wrong here if someone is more knowledgeable...
The Olds 425 will only easily take a Big Block Olds (400/425/455) oil pan. Anything else may have to be modified (probably a lot) in order to bolt on the engine.
The 65/66 Starfire is a B-body chassis, and as such has the steering linkage behind the engine crossmember, which makes the clearance different than the 68 & up cars, and had a fairly unique pan.
So, to answer your original question...
For ease of installation, and a minimum amount of hassle, you want to get a 65/66/67 oil pan off a B-body, big block engine. That will be a direct bolt in with no clearance issues.
I remember back when I rebuilt the engine on my original starfire (in 90-91 or thereabouts), while it was out, we tried to test fit an Olds 455, Buick 455, and a Pontiac 400 in the engine bay, just because we had them lying around at the time and wanted to see if one would bolt in to get me up and running for a while to play with while the original engine was being built.
None of them would fit for various reasons, and even the newer Olds 455 oil pan would not clear correctly from where the steering & engine crossmember were on that chassis.
I think I'm right on this info, but please correct me if I'm wrong here if someone is more knowledgeable...
Last edited by GTI_Guru; Nov 15, 2011 at 02:48 AM.
"me somebody" site member
Joined: Jul 2007
Posts: 1,612
If you are new to the Starfire, I have one piece of advice:
If you are having problems finding parts for the car, or if repair shops say they can't find parts for it, then tell them that the car is a Delta 88. Those 2 models share at least 95% of the same components, but the Starfire was rare enough that it just doesn't register in some parts databases. To pick a random example -- master brake cylinder. Doesn't show up in parts databases under the Starfire. But look for a Delta 88, and half a dozen appear.
If you are having problems finding parts for the car, or if repair shops say they can't find parts for it, then tell them that the car is a Delta 88. Those 2 models share at least 95% of the same components, but the Starfire was rare enough that it just doesn't register in some parts databases. To pick a random example -- master brake cylinder. Doesn't show up in parts databases under the Starfire. But look for a Delta 88, and half a dozen appear.
The 65/66 Starfire is a B-body chassis, and as such has the steering linkage behind the engine crossmember, which makes the clearance different than the 68 & up cars, and had a fairly unique pan.
For ease of installation, and a minimum amount of hassle, you want to get a 65/66/67 oil pan off a B-body, big block engine. That will be a direct bolt in with no clearance issues.
I remember back when I rebuilt the engine on my original starfire (in 90-91 or thereabouts), while it was out, we tried to test fit an Olds 455, Buick 455, and a Pontiac 400 in the engine bay, just because we had them lying around at the time and wanted to see if one would bolt in to get me up and running for a while to play with while the original engine was being built.
None of them would fit for various reasons, and even the newer Olds 455 oil pan would not clear correctly from where the steering & engine crossmember were on that chassis.
I think I'm right on this info, but please correct me if I'm wrong here if someone is more knowledgeable...
For ease of installation, and a minimum amount of hassle, you want to get a 65/66/67 oil pan off a B-body, big block engine. That will be a direct bolt in with no clearance issues.
I remember back when I rebuilt the engine on my original starfire (in 90-91 or thereabouts), while it was out, we tried to test fit an Olds 455, Buick 455, and a Pontiac 400 in the engine bay, just because we had them lying around at the time and wanted to see if one would bolt in to get me up and running for a while to play with while the original engine was being built.
None of them would fit for various reasons, and even the newer Olds 455 oil pan would not clear correctly from where the steering & engine crossmember were on that chassis.
I think I'm right on this info, but please correct me if I'm wrong here if someone is more knowledgeable...
Certifiable car addict...
Joined: Apr 2011
Posts: 392
From: SW Ohio
hmm. okay. I could have sworn there was a difference. Like I said though, it's been 20 years since I tried it.
Good to know for future reference.
Might there be a clearance issue with ones that have the exhaust crossover pipe vs. the dual exhaust setup then... Now I'm scratching my head as to why it didn't work. I knew there was some issue that wouldn't fit right.
Good to know for future reference.
Might there be a clearance issue with ones that have the exhaust crossover pipe vs. the dual exhaust setup then... Now I'm scratching my head as to why it didn't work. I knew there was some issue that wouldn't fit right.
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