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TR2/3/3A Manual for the Laycock de Normanville Overdrive Unit

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hit_n_miss

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I recently bought off eBay a manual for the overdrive unit that purported to be for TR2 through TR4. The Triumph Part No. for the manual is 502274. My concern is that the Forward for the manual says that it is for units fitted to the Standard Vanguard, Triumph Renown, and TR2. No mention of the TR3 (which I have). The manual also says that on the TR2, the overdrive only affects top gear.

In the TR3 Practical Hints manual, under optional equipment, they say that the overdrive applies to 2nd, 3rd, and top gear. That was my experience using the overdrive (before it quit working).

The eBay seller says that this is the correct manual for the TR3A (and other TR3s). I don't think it is; I think that this is an earlier manual. Thoughts? Comments? Does anyone know of the availability of the "correct" manual for a TR3A overdrive unit?

It's possible that this manual may be sufficient for me to diagnose / fix my unit (probably an electrical fault, possibly oil level).

Thanks. Arnie
 
Arnie-

I'm pretty sure that's the standard manual thats out there - the A-type overdrive design itself really didn't change from the earlier models. Just in case, have you ever met Ed Woods? I think he's in the Pittsburgh area and he knows more about these overdrives than most ever will - he may be a very handy resource for you to help you sort things out.

Randy
 
As far as I know, that is the only separate manual that Triumph ever offered for the A-type. Yes, it is somewhat dated, many of the details are incorrect for the later cars (like operation in 2nd & 3rd, pressure specs and so on). There were several other modifications along the way, like larger operating pistons and a smaller accumulator (for the IRS cars). But it still has a lot of good information about troubleshooting, how the whole thing works, how to adjust the solenoid and so on.

Best factory reference that I know of is the TR4 workshop manual. Unfortunately it has little or nothing about troubleshooting. But there is a good article on troubleshooting written by a fellow enthusiast at https://www.buckeyetriumphs.org/technical/AOD/AOD5/AOD5.htm

Or you could ask here. Lessee, it must've been around 1975 when I bought a TR4 just to get the overdrive, and put it in my TR3A. I've been nursing one or another around pretty much ever since :smile:

PS, forgot the links. TR4 manual:
https://drive.google.com/file/d/0B2...YWExLWIyNjctOTYzNmI3OTg2ODM0/edit?usp=sharing
OD manual:
https://drive.google.com/file/d/0B2...N2Q3LWJmZTUtMTRkN2MxNDI4M2Vj/edit?usp=sharing
Another document that might be helpful:
https://drive.google.com/file/d/0B2H2NJt34OffcVp0TUJiU29Sa214cXVOQzJCTGJXUQ/edit?usp=sharing

Also, those old manuals recommend using 30 or 50 weight motor oil. Triumph changed their minds around 1959 or 60 and started requiring (as in void the warranty if you don't) 90 weight GL4 gear oil instead. Personally, I use RedLine MT-90 which is a full synthetic GL4 oil that has been optimized for use in synchronized manual transmissions. It didn't seem to make a lot of different to the OD, but sure made a noticeable difference in the main gearbox. Kind of pricey, but worth every penny, IMO. (Some shopping around may produce a much better price as well. I found it on Amazon for half what the local store wants.)
 
Nelson Riedel (the author of the Buckeye articles) used some of the info&drawings from the OD manual, in his writings, but his articles contain far more in depth info. The manual might be nice to have from a collector's stand point, but is not to helpfull for repair or overhaul. The VTR articles and the Haynes manual are also good sources.
Berry
 
Thanks for the prompt and comprehensive replies. You folks never disappoint. Once I start the troubleshooting, I'm sure that I'll be back with more questions. :cool:)

Arnie
 
Randy, I see that Ed Woods is also a member of the Western PA Triumph Association and I now have his email address. I'll probably contact him at some point. Thanks. Arnie

TR4nut said:
Arnie-

I'm pretty sure that's the standard manual thats out there - the A-type overdrive design itself really didn't change from the earlier models. Just in case, have you ever met Ed Woods? I think he's in the Pittsburgh area and he knows more about these overdrives than most ever will - he may be a very handy resource for you to help you sort things out.

Randy
Click to expand...
 
My A-type is on the rebuild schedule for December...as always I plan to be abnormally intense on a thread about it...
 
If you scroll down here https://www.acmefluid.com.au/larry/servicing.html you will get to a scan of the overdrive handbook for the Healey 100, it is the A-type O/D, some neat drawings of the mechanism and period artwork, but not sure of the practical value, the Healey unit was wired up differently with a throttle switch and a centrifugal switch which prevented it from turning on below 40 MPH or so, the throttle switch prevented it from disengaging unless you had part throttle engaged, the TR didn't have either of these, but the internals should be the same.
 
CJD said:
Hey Randall...all I get is the first page of your links. Is there a trick to it?
Click to expand...
Shouldn't be any trick, but the magic doesn't always work. My suggestion would be to download the entire file to your hard drive using either the V icon, or File/SaveAs.

If that still doesn't work, let me know and maybe we can work something else out. This link should let you browse the entire collection:
https://drive.google.com/folderview...yMy00ZDhkLTliOWEtOWU1OWRhNDZhYmRl&usp=sharing
 
I have been using both Chrome and Internet Explorer lately due to problems with another forum and IE, in this case IE actually works better for viewing, in Chrome I don't get the scroll bar to view it, I think your only choice then is to download it to view it, I tried poking around and couldn't figure out any other way.
 
Last edited:
FWIW, Firefox works well for me. I particularly like the variety of add-ons that allow you to customize controls (like which sites can run scripts on your computer).
https://www.mozilla.org/en-US/firefox/new/
 
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