Thornton-Welles locking differential

[Tony Smith]

Whoa, slow down a little. The thread seems to have shot off on a tangent here.

The FGT Parts book is not talking about a 6x6/Tandem drive to convert a vehicle by utilising a Welles-Thornton rear bogie. The book is discussing an optional locking differential centre to be used in a 4x4 FGT.

C11Q-4299 Thornton-Welles Automatic Locking Differential (Optional, when specified).

The only other allied vehicle I can find reference to in WW2 having any kind of locking differential is the IH M-5H-6 6x6 trucks, with Thornton diffs. Are these the locking centres, or the tandem bogie arrangement? See: http://www.onallcylinders.com/2013/1...erential-town/

Curious the variations of Thornton-Welles and Welles-Thornton, which seem to relate to the US Supplier/Canadian Distributor relationship rather than any trade name or patent right (which seems to lie solely with Ray Thornton).

(Funny how this thread has sat dormant for 12 years and suddenly springs to life again.)

[Lionelgee]

Originally Posted by Tony Smith

Whoa, slow down a little. The thread seems to have shot off on a tangent here.

The FGT Parts book is not talking about a 6x6/Tandem drive to convert a vehicle by utilising a Welles-Thornton rear bogie. The book is discussing an optional locking differential centre to be used in a 4x4 FGT.



The only other allied vehicle I can find reference to in WW2 having any kind of locking differential is the IH M-5H-6 6x6 trucks, with Thornton diffs. Are these the locking centres, or the tandem bogie arrangement? See: http://www.onallcylinders.com/2013/1...erential-town/

Curious the variations of Thornton-Welles and Welles-Thornton, which seem to relate to the US Supplier/Canadian Distributor relationship rather than any trade name or patent right (which seems to lie solely with Ray Thornton).

(Funny how this thread has sat dormant for 12 years and suddenly springs to life again.)

Hello Tony,

My reading of the (optional when specified) was that the Thornton diffs could be supplied as an option if the buyer specifically asked for and was prepared to pay for them. So the option of the Thornton diffs like a factory fitted radio in a Holden Belmont was there if one wanted to pay for it. Otherwise Belmonts were the no frills base model and did not come with a radio as standard. The Premiers did though.

My reading of the posting by "Grandad" in my last post suggests that the Thornton diffs are the self locking ones .... Grandad states that "Ray Thornton designed the two-speed transfer box with a self-locking diff in it that later came out in 1939 as the NoSpin, which became the Detroit Locker...." Accessed August 4th 2016 from, http://www.hcvc.com.au/forum/OldTruc...n-names#104467

Kind Regards
Lionel

[Tony Smith]

This page discusses the experimental conversion of F60H chassis with Thornton bogies and a single locking differential, but it ultimately appears to have been an experiment, and not a production vehicle.

Perhaps this trial led to the approval of the Thornton locking differential to the 4x4 FGT?

[Lionelgee]

Originally Posted by Tony Smith

This page discusses the experimental conversion of F60H chassis with Thornton bogies and a single locking differential, but it ultimately appears to have been an experiment, and not a production vehicle.

Perhaps this trial led to the approval of the Thornton locking differential to the 4x4 FGT?

Hello Tony,

Yes that post is the one that I posted up a couple of hours ago. Accessed August 4th 2016 from https://servicepub.wordpress.com/201...illery-tractor

Kind Regards
Lionel

[Tony Smith]

Originally Posted by Lionelgee

Hello Tony,

Yes that post is the one that I posted up a couple of hours ago. Accessed August 4th 2016 from https://servicepub.wordpress.com/201...illery-tractor

Kind Regards
Lionel

That's true, but I thought you were referring to the tandem bogie conversion, and not the locking differential.

[Lynn Eades]

Tony, The No spin Diff is just that. It is the carrier with spider and side gears with a spring between the side gears and teeth (dogs) on the inside of the carrier housing and on the outside of the side gears. They lock under load and click when half shaft speeds were un equal. We had one for a Wagner log stacker made by Allied sevices in Oregon, which I built into a diff about 20 years ago.

Also, the famous Detroit locker was (I believe) designed and built for the 1 1/2 ton 6x6 Dodge, for the mud in Europe. The building with the plans (patents?) was burned down. I can't remember where this came from, other than in Dodge stuff.

[Lionelgee]

Hello All,

As previously stated in my earlier email where I cited "Grandad". Thornton made the "Nospin" diff. Later Thornton were brought out by the Detroit Locker people. Accessed August 4th 2016 from, http://www.hcvc.com.au/forum/OldTruc...n-names#104467

This has been verified by another author who states that ...

Detroit Locker
After being used as a compensator between the two axles of the Thornton Tandem Drive (a dual rear axle conversion for single-axle trucks), it appeared as the Thornton NoSpin differential in 1939, and was eventually used in a large number of WWII military trucks. At points in the 1950s and 1960s, it was an OE option in OE light trucks. It began hitting the light truck aftermarket in 1969 as the Detroit Locker. Major improvements came in 1994 with the incorporation of a dampening device that civilized the Detroit without changing its basic operation. Accessed August 5th from,
http://www.offroadadventures.com/articles/view/id/432

Here is the link to a third source that provides the History of the Detroit Locker. Accessed August 5th from, http://www.onallcylinders.com/2013/1...ferential-town It states that... "The Detroit Locker was initially called a “Thornton NoSPIN Differential.” Ray Thornton patented it in 1941 as device for use in six wheel (tandem drive) truck applications. The NoSPIN was manufactured by the Detroit Automotive Product Corporation and was used on American military vehicles during World War II."


Kind Regards
Lionel

[gordon]

A Detroit locking diff, and very useful it was. I know you are talking Fords here, but don't forget all the Dodge WK60 had Welles-Thornton back bogies too.

I suspect they hoped ( in vain ) that using locking diffs on both the back axles would make up for the lack of drive to the front axle - fat chance

[Tony Smith]

This page details the intricacies of the Thornton tandem axle conversion (which apparently sold well into the 50's). From this description, it appears the Thornton locker was actually used between the drive to the middle and rear differentials, and not within an axle differential between left and right axle shafts. However, the depiction of the locker is precisely the same as modern day units sold as "Detroit NoSpin" lockers, which install within the differential and replace the pinion or spider gears. It is not technically impossible that this centre was fitted within the rear differential in the 4x4 FGT.