A-type Overdrive Model Number

[CinneaghTR]

A very nice guy in big white truck just delivered an A-type overdrive to my house. It looks pretty good on the outside, but I won't be able to check it out thoroughly until this weekend with an expert/friend (Thanks, Jesse!) who is helping me out.

In the meantime, I have a question about the model number:

22/1374

Moss had a 6 thrown in there (61374) on its id page, but the great information on the web (from a lot of BCF members I might add) set me straight with that. I am happy it is a 3/4 box with the 2-3-4 capability. Good stuff!

Would you guys have any thoughts on why the second "2" appears to be stamped over another number that looks like a "6" or an "8"? Factory boo-boo?

 

[CinneaghTR]

Oh, and I might as well ask this while I am at it, the gearbox has the stamping CT15189 on it. Is there a listing that could provide an approximation of the actual car application and ballpark year?

 

[TR4nut]

Well the 22 is the final overdrive ratio, so maybe this was less a mistake than a configuration change? I thought Healey's used 28% overdrive, but that would make it an 8 instead of a 6..

 

[TR3driver]

the gearbox has the stamping CT15189 on it.

That would make it from a 62 TR4.

 

[Moseso]

Randy is correct that the A type ODs came in two ratios, 22% and 28%. TRs came equipped with 22% ODs, when they had them at all. I don't know where the 28% ones were fitted. The first two numbers, "22" or "28," before the slash, denote the ratio -- which, of course, could have been changed at some point in the 50 years since it was originally built/stamped. My OD has a "28" model number, but has a 22% gear set in it.

Either one will work fine in your car, with a 28% giving a little taller gearing, overall, and a 22% providing better intermediate ratios, when used between 2nd and 3rd, or 3rd and 4th.

 

[TR3driver]

Randy is correct that the A type ODs came in two ratios, 22% and 28%.

I believe there were other ratios available as well; for example the Moss catalog shows early AH BN1 as having a 32% OD.

 

[CinneaghTR]

Thanks for your input, guys. I am excited about getting the OD in the car!

 

[HerronScott]

So just curious where you picked up your O/D at?

Scott

 

[CinneaghTR]

Nowhere special. eBay.

 

[HerronScott]

Was interested in case there was some place else I should keep an eye out for them. The 2 TR4A's have overdrives but the TR3 doesn't so I'll be interested in picking one up for it if the right deal comes along. I've got a couple parts ones, but I don't think that I have enough to make a whole one. One of the parts ones I honestly dug out of the dirt in the remains of a TR3 frame in an old fashioned junkyard. Someone had taken the transmission and left the overdrive! :frown:

Scott

 

[sail]

I bought mine from a guy who lists on ebay by "Roslian" and is in New Zeeland. Nothing listed at the moment but he often will have a rebuilt od listed. 100% feedback. Fair price. Nice guy. It works. Shipping was included in the price he gave me and got it the next week. Don't see his email right now but pm me if you get the urge and I will find it.

 

[CinneaghTR]

He sells just the ODs and the bits you need to connect them to the tranny, right? I thought his prices were good and his feedback was good, too. I did a search on another list and some TR owners had some bad experiences regarding the condition of the ODs when they arrived so I shied away, but I am glad to hear that you had a good experience. Maybe I'll rethink that for Dear Old Dad's 4?

 

[sail]

He sells just the ODs and the bits you need to connect them to the tranny, right? Maybe I'll rethink that for Dear Old Dad's 4?

Yep, OD, adapter plate and shorter shaft. I put his shaft in my box. No worries mate....I take that back, don't want to curse you.

Man I wish my dear old dad had a TR. He left me with a 1980 Grand Marquis. What a sled.

 

[HerronScott]

Richard,

Thanks for the info!

Scott

 

[CinneaghTR]

Man I wish my dear old dad had a TR.

I'm a lucky guy. Dads and TRs are a winning combination. Thanks for the kind words.

All these 4As are looking good in this thread.