TR6 versus Tr3 driveshaft

[Trperson]

I have a tr6

Bought aTR 3/4 overdrive, it came with a new looking driveshaft.

Any difference in a tr3/4 and tr6 driveshaft?

Length or anything else? thanks

[Steves_TR6]

Do you mean the propshaft ?

[astontr6]

Hi!

Can we have your name? Same question as above? The TR3/4 overdrive is not exactly the same unit that was fitted to the TR6. BL had mods done to the A type, to lessen the force of engagement. This was done to protect the diff. mounts and drive shafts? Early TR4 IRS had lots of warranty claims, in this area!

 

If it was me, I would take your unit to ORS in Sheffield and have them modify it as per TR6, by using the later accumulator etc. and replace the gearbox lay shaft ( one of the most common gear box failure points) and modify the needle roller bearings on the lay gear to 3 off, as per the Stag. They can also supply the full conversion kit, from non o/d gear box to o/d gearbox. .

 

Bruce.

[stuart]

Yes the prop is the same just the flanges are a different shape.

Stuart.

[Motorsport Mickey]

Hi Trperson,

 

Maybe we are thinking you are familiar with the differences between the TR2/3/3a/4 and the IRS (independent rear suspension cars) which cover TR4a/5/6 range and you aren't ?

I trust you won't find it simplistic but the differences in this area you're asking about (there's differences in others but it's not necessary to trawl through all the spec) are as follows.

 

Lets try a little comparison, the sidescreen cars (TR2/3/3a) and the TR4 all have what is called a "live" rear axle or more crudely a "cart" axle. This is a solid axle casing running from side to side of the car to the wheels, it doesn't have driveshafts, it has halfshafts, these are one piece solid shafts which connect from the diff unit in the centre of the axle and run to the outside of the axle to the wheel. Connecting up to the diff unit and running forward to the rear of the Overdrive unit (or gearbox if no overdrive fitted) is the prop shaft (correct name the propeller shaft, so called because it propels the car). This propshaft has a sliding joint in it to allow for the small variations in operating length that will occur between the gearbox and the rear axle in use.

 

The IRS (independent rear suspension cars) which cover TR4a/5/6 range do not have a rear axle. They have a separate diff which is mounted onto the chassis around about the centreline of the car, from the diff unit there are connected diff driveshafts which connect up to the wheels on either side of the car. As the name suggests these driveshafts transmit drive to the wheels from the diff unit, and connecting up to the diff unit and running forward to the rear of the Overdrive unit (or gearbox if no overdrive fitted) is the prop shaft (correct name the propeller shaft, so called because it propels the car). This propshaft has a sliding joint in it to allow for the small variations in operating length that will occur between the gearbox and the rear axle in use.

 

As you can see from the descriptions the connection from the diff to the overdrive in either group of cars is called a propeller shaft which is where your question is "throwing" some of the forum members who'd like to answer your question. If I've summed up your circumstances correctly both group of cars use a propeller shaft which is broadly the same length in all cases and has a sliding joint in the centre, other than any flange variations I believe the hole centres will line up and so the propshaft will fit from a sidescreen car onto a IRS car. That is unless I've got it wrong and you are talking about driveshafts ?

 

Mick Richards

 

Edit: see that's the trouble with detailed responses you get beaten to the conclusion by "quick draw McGraw" Stuart who succinctly summed it up, lol.

Also Bruce has pointed out the operation of the TR3/4 overdrive unit is very "brusque" and when fitted to the original IRS cars (and they were Tr4a cars using about the same power and torque) lead to advanced failure of the diff mount area on the chassis frame. This lead to the overdrive operation being "softened" in use to prevent this, if you fit to a TR6 with more power and torque maybe worth modifying yours before fitting.

Edited December 20, 2016 by Motorsport Mickey

[BlueTR3A-5EKT]

Something tells me that the prop shaft of a 3 synchro car is a touch longer when fully extended than a 4 synchro.

 

That said......

We used to sell TR6 propshafts (as that was all that was available from StanPart at the time) for all TR models 2-6 needing a prop shaft, and I do not recall ever having a complaint; that included overseas sales to the somewhat picky German market.

 

Peter W

[stuart]

Something tells me that the prop shaft of a 3 synchro car is a touch longer when fully extended than a 4 synchro.

 

That said......

We used to sell TR6 propshafts (as that was all that was available from StanPart at the time) for all TR models 2-6 needing a prop shaft, and I do not recall ever having a complaint; that included overseas sales to the somewhat picky German market.

 

Peter W

That may just be due to the shape of the flange.

Stuart.

[Don H.]

FWIW, "drive shaft" or "driveshaft" are perfectly acceptable terms over here for a British "propshaft". Any of them are OK. The things that go from the differential to the hubs can easily be called "axle shafts" (or "half axles" especially for IRS cars) in the USA.

 

We probably aren't as sensitive to the semantics.

[Guest ntc]

That may just be due to the shape of the flange.

Stuart.

+1 and correct

[Motorsport Mickey]

FWIW, "drive shaft" or "driveshaft" are perfectly acceptable terms over here for a British "propshaft". Any of them are OK. The things that go from the differential to the hubs can easily be called "axle shafts" (or "half axles" especially for IRS cars) in the USA.

 

We probably aren't as sensitive to the semantics.

Which is exactly why anybody posting on this forum without giving us an idea of where they are based and an accurate description of what they are asking about risks not getting very accurate or even any replies.

I'm on a couple of other car forums where unless you complete your signature with an accurate self written description of Marque and model of your own car and other relevant spec the moderators recommend to other members that you don't reply to their enquiry. It's too easy for the thread to run to 15 posts before the originator of the enquiry decides to disclose that the car is an imported Japanese model and oh...it's diesel !

I really believe we try to cut some slack for new members or owners but often they are their own worse enemy, a description of either halfshaft or driveshaft is more easily assimilated if we know the poster is a US member (that's where an accurate signature comes in) and likely to use either of those terms for the one item. If a US poster talks of hood or fender we know what those terms mean which of course is different from a UK poster...how do we know what items are being talked about ?

That's why I gave a detailed reply above to allow the poster to define which items or nomenclature are correct and which actual items they were asking and wanted a reply on.

Stuart bounced my reply anticipating that drive and propshafts were intermingled here which is my assumption also, but we don't know, it's a guess which is why the first 2 responders were not able to give as much info as the thread poster no doubt wanted. 24 hours on and we so far haven't got further feedback to work on.

 

Mick Richards

[Don H.]

I'm with ya, Mick! This is a small and personal forum -- we're all on a first name basis (or at least willing to be) and knowing where someone is can make a difference in the advice given.

[foster461]

FWIW, "drive shaft" or "driveshaft" are perfectly acceptable terms over here for a British "propshaft". Any of them are OK. The things that go from the differential to the hubs can easily be called "axle shafts" (or "half axles" especially for IRS cars) in the USA.

 

We probably aren't as sensitive to the semantics.

 

It was pretty obvious what the OP was asking about because the OP provided the context. There are times where if you dont provide that context (or your planet of origin) that asking about driveshafts will cause confusion.

 

eg, my TR6 driveshaft splines are worn, what should I do ?

 

Stan

[dingle]

I think the bottom line is that the driveshaft or propshaft didn't change from TR2-TR6, regardless of whether OD was fitted or not.

Berry

[stuart]

Having quite a lot of dealings with our Colonial Cousins is why I just answered with propshaft info.

Stuart.

[Motorsport Mickey]

Having quite a lot of dealings with our Colonial Cousins is why I just answered with propshaft info.

Stuart.

I'm impressed Stuart, reading his initial enquiry I couldn't see anything that gave an indication of his nationality or what area of the world he lives in, hence my comment about lack of information and the previous 2 posters querying his description of what he was after.

 

Mick Richards

[Trperson]

 

Yes the prop is the same just the flanges are a different shape.

Stuart.[/quote

 

I'm across the pond, this is the shaft from trans to rear end, guess you guys call it propeller shaft. The one that came with the overdrive looks almost new so thought I'd use it. I haven't taken the shaft out of the tr6 yet so hadn't had a chance to compare them. Sounds like I can use either. Robert

[Tom Fremont]

While we're on the topic, I'd like to see some opinions on why fitting a propshaft to the diff flange in its alternate position (180 degrees ) can produce a vibration where it wasn't before ( or at least was minimal ).

 

Cheers,

Tom

[Motorsport Mickey]

Different position of grease nipple ?

 

Mick Richards

[Waldi]

If the shaft would have only one UJ, the outgoing shaft would have a sinoid shape velocity when the ingoing shaft would rotate with constant velocity; the addition of a second UJ can compensate this (counteract), but for this it needs to be " in phase" with the first UJ.

On the drive shafts (dif to wheel hub) for example, this is ensured with the spline design, one spline is wider than the rest so the 2 halves cannot be installed out of phase.

Hope I expressed correct, sorry for not being US or UK:)

Regards,

Waldi

[RogerH]

There was a post only a couple of weeks ago showing this in a video clip.

 

Roger

 

Here it is http://pantera.infopop.cc/eve/forums/a/tpc/f/9550045562/m/4561020956

Edited December 21, 2016 by RogerH

[Waldi]

Wow, thanks Roger,

I saw that too and forgot about it, and am only 54!

TMI processed in this boy's brains.

Waldi

[Tom Fremont]

It is generally known that Cardan type universal joints are not " constant velocity " and that fitting 2 inline with the flanges parallel will cancel out their velocity fluctuations. Where one is required it is customary to use CV joints, as is the case when the ends go out of parallel in service ( e.g., front drive ).

 

I've never seen a plausible explanation for this in the 43 years I've been driving TRs ( and chasing down vibration issues from time to time ) but I have seen recommendations to mark the relationships of the mating flanges when removing a prop shaft to ensure refitting as before. I always blew that off, but last summer I saw it again and thought to try it due to a slight but detectable vibration at 70-80 mph. A quick test run had me under it again to put it back!

 

Cheers,

Tom