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steved69tr6

Stag Gearbox In TR6 A-Type

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Hey guys

 

My TR6 has an A-type overdrive gearbox, and the layshalf and input shaft are knacked, however the overdrive is good. I've just brought a Stag re-con gearbox with an A type overdrive bolted to the back. My plan is to switch the gearboxes over, so to use the TR6 A-type Overdrive on the Stag gearbox. What else do I need to do?

 

Cheers

 

Steve

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Hi Steve

 

Am in the process of doing this same thing with my TR5. It's a good idea to check to make sure that you really do have a box that started life in a Stag. Many saloon boxes have ended up in Stags because they were more plentiful and therefore easier to come by. Stag boxes have serial numbers that start LD or LE. The Stag box has some improvements over the TR box ie. more and larger laygear bearings and all steel bushes. Unfortunately they do use a different constant pinion to the TR boxes and as you say yours is damaged it will mean you'll need a TR item from somewhere. I was told that the Stag clutch operating shaft is different from the TR but that the fork is the same. I used both from my TR box. The Stag front cover is also longer but this can be replaced with the one from the TR box. As for the overdrive, I'm not too sure how the Stag A type differs from the TR item ( the mountings may be different and also the gearing for the speedo take-off ) but they can be swapped over as a unit. Hope this helps a little.

 

Peter

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Thanks Peter,

 

Some good info there

 

Well on my TR6 box the primary input shaft is only worn out due to the bearings, but the gears are fine, no sharp teeth or chips. Do you think it would be possible to us this on the stag box, and just swap the bearing to stag ones?

 

Cheers

 

Steve

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Hi Steve

 

If the constant pinion is undamaged then it's relatively simple to replace the Stag item with the TR one. The constant pinion and the constant gear used to only be available as a 'pair' and you could swap the constant gear over as well but this would require just about totally stripping the box. I see that Moss sell the constant gear as a used item so I guess that the 'pairing' isn't perhaps all that critical. If you don't swap them as a pair you'd need to ensure that they have the same helix angle. A word of caution, with any box that you know has been tampered with (which by now is just about all of them) it's best not to assume anything about the origin of it's parts. It's also worth reading Pete Cox's notes in the relevant sections of the Moss parts catalogue, his experience of the subject is legendary!

I should make it clear that this is only based on my experiences and that I am no expert on the subject. I accept no liability for any errors or omissions.

 

Peter

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My TR3 has a Stag box with TR6 input shaft and TR6 A type overdrive.

 

The input shaft (the one that pokes in the clutch) is longer on a Stag than TR2-6. You will need to fit the TR item. Check which size bearing it uses to fit with the mainshaft - there are two sizes available for A type.

Stag A type I think you will find has a different rear mount to a TR2-6, so rear case change is needed or special mounting system/adaptor.

Solenoid is vertical on TR but I think horizontal on Stag. Check the drive flange mates with your propshaft BEFORE you get it all in the hole as start speaking in tongues.

I also had to get my speedo recalibrated for the gearbox/overdrive once the car was running as it was adrift speed wise.

 

 

Cheers

Peter W

Edited by BlueTR3A-5EKT

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I converted my non-o/d TR6 gearbox from a Stag o/d box many years ago and I recall the solenoid was horizontal, pointed to the rear of the car. It required the removal of a tiny section of the floor pan out flange to give it clearance to the solenoid & make it fit.

 

Mod wasn't noticeable when the cover was refitted.

 

Mark.

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Cheers guys all very good info, I've currently got a non overdrive (Spare) gearbox that I striped a few years back that I was going to rebuild, but as a non overdrive gearbox is worthless it remained in bits for spares, and its parts are in very good condition. I might use the primary input shaft, and second motion shaft from that in my new Stag box. As for the overdrive, well my Stag A-type overdrive is scrap to me, I'm raiding the one that's currently in my TR6, and is a genuine TR6 A-Type overdrive. Thanks for the words of warning Peter W about the two types of overdrive units. I'll let you all know how I get on with this conversion as I do it

 

Cheers

 

Steve

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Cheers guys all very good info, I've currently got a non overdrive (Spare) gearbox that I striped a few years back that I was going to rebuild, but as a non overdrive gearbox is worthless it remained in bits for spares, and its parts are in very good condition. I might use the primary input shaft, and second motion shaft from that in my new Stag box. As for the overdrive, well my Stag A-type overdrive is scrap to me, I'm raiding the one that's currently in my TR6, and is a genuine TR6 A-Type overdrive. Thanks for the words of warning Peter W about the two types of overdrive units. I'll let you all know how I get on with this conversion as I do it

 

Cheers

 

Steve

 

 

Your Stag A type is not a scrap item, it has value to someone without overdrive.

 

Cheers

Peter W

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Oh yes, I know this, I just meant it as an expression scrap to me, but good for eBay :)

 

I now have my Stag box, hears the first pic of many

 

 

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Mismatched gear sets are a certain recipe for noise . It may be non-destructive but it will sound like a worn out 'box :( . This is why sets have traditionally been preferable to single gear replacement.

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Hence using matched gears from a good spare TR6 gearbox I have. The input shalf and constant gear on the layshalf have been swapped for TR6 items, and are matched. The rest is Stag

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Right so, got the gearbox in and perfect in every respect, silent as ever. BUT BUT BUT the fecking overdrive don't work!! It worked when it was fitted to the TR6 box, but now that its fitted to the Stag box it don't want to know. I've adjusted solonoid bracket correctly to the manual, still nothing. all electrics are working normally. I read up in the Moss catalogue about bleeding air out of the overdrive, is that worth a try? Anyone got any ideas as to why my overdrive isn't working?

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Are the springs on a stag A type not stronger than the TR ones ???

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