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MG TD TF 1500 - Laycock J Type Overdrive/Triumph trans transplant

This very well respected Ford Research engineer, Tom Stockton, is now over ninety. A half century ago, he retrieved a new Laycock J Type overdrive out of the scrap and saved it; I picked it up to see what the heck can be done with it.
I see it was most popular with Volvos, but it did make it onto Triumph trannies as well. It does not APPEAR to bolt to the T type trans, but what's the issue of planting one of the Triumph transmissions onto the T type bell housing?
I can see making the effort to attach it to one of our TDs considering Tom gave it to me.
...Otherwise, I'll list it on Ebay, probably in vain. to finally find a home for one of his thousands of trinkets.

JIM
Jim Northrup

Jim,

The problem is not with adapting it to the XPAG engine, but that the whole unit becomes too long, requiring cutting and refitting the cross member.

I for one, wouldn't feel comfortable, playing with the geometry of the chassis.

I would not consider it as it is entirely problematical, whereas, a 5-speed kit would be much more practical, and likely to cost about the same in the end.

... all because of being tempted by a "free" OD.

Gord Clark
Rockburn, Qué.
Gordon A Clark

Gordy,
I have no hesitation to modify the cross member & shorten the driveshaft. The final ratio of 4.10 would go great with our Marshall blown 1250 XPAG.

This overdrive would have real sentimental value, rather than just shelling out bucks for a 5 speed. Tom was a walking automotive encyclopedia, taught steam engines classes and was pretty much an authority on most antique engines & equipment. There is an engine museum on his farm, and the scale steam locomotive he built still has its tracks at Dominos Farms.

Jim
Jim Northrup

First you need the trans, to suit overdrive. Not easy changing one from straight to OD. Different mainshaft and rear case/adapter to OD.

I never kept track of OD designations. If this is for a TR2/3/4 box, they have integral bellhousing. If Spitfire/GT6, separate bell, smaller unit, gearbox break lots more. And Triumph was forever changing internal gearbox bits in an attempt to fix them; it was almost impossible then to get all the correct pieces when rebuilding broken ones - lots and lots of broken ones, GT6 straight off the delivery trucks. And I worked for two Triumph dealers.

We also handled Volvo, in the dealership and later in my shop, many. I don't think I ever saw a Volvo box apart. Volvo is separate bell also. Most Volvo do not have a remote shift, so stick position might get difficult. Possibly P1800 had remote, can't remember.

FRM
FR Millmore

jIM,
HERE IS A SIMILAR UNIT

STEVE WINCZE

PAGE #2
DENIS BAGGI IS A CONTRIBUTOR TO THIS FORUM...

STEVE WINCZE

Steve,

Thanks for the info. Interesting someone marketed a standalone overdrive unit.
What I was given needs to probably have an adapter casting and a different shaft to fit to Triumph tranny. That can happen. I'm wondering, though, on how much modification is required to bolt the Triumph trans onto the TD bellhousing, or Triumph bellhousing to XPAG, and what clutch parts switching/modifications are needed.
I also expect someone to jump up and announce the MGB trans with OD is the way to go.

JIM
Jim Northrup

The MGB overdrive transmission is much larger than the TD/TF transmission. Mimthink it would be a logistical nightmare to make it fit. The Triumph transmissions from the Spitfire MK IV and TR7 are not that large, from memory. There was an overdrive unit avalable, and the TR7 was also avalable with...a five speed.
Hmmm. I wonder if anybody has worked with either of these transmissions for a T type conversion.
-David
D. Sander

I like the idea of the OD being attached to the trannie output at the "U" Joint flange,,, seems like it would be an easier instalation, rather than trying to adapt it right up to the trannie. A friend of mine over here did that to an old 1940 Caddie Limo that he built.
SPW
STEVE WINCZE

I've seen an MGB OD gearbox on a TD. I'll try to dig up some photos of the installation. I agree though, it's a huge lump compared to the original. Heavier by quite a bit, too.
Steve S

This thread was discussed between 27/06/2012 and 29/06/2012

MG TD TF 1500 index

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