TR5 Gearbox

[MJK]

Hi All,

I've had my TR5 since the mid 1990's when it was totally rebuilt and had pretty light use since. During the rebuild (and for reasons I can't recall) might the o/d gearbox been replaced with a 4 speed box? The boot is badged as an o/d car. Whilst the 4 speed box is fine, I am contemplating upgrading it to an o/d unit.

Is it worth it? Financially and practically.

I am getting conflicting comments on how many gears should have o/d. Internet research suggests gears 2,3 and 4 but ORS in Sheffield have said only gears 3 and 4. Can I seek views on which is correct please.

My main objective is authenticity and whether it's worth doing. I would describe the overall condition of the car currently as in very good condition so I don't think it would be investing in a rust bucket.

Many thanks for your thoughts.

Best regards,

Malcolm

 

 

[RobH]

It's certainly worth it practically as it makes long distance cruising much more relaxed and it gives you extra intermediate gears which is useful and fun.  There are two types of overdrive used on TRs - an A type OD will work on 2/3/4, the J type is supposed to work only on 3/4 but it can be made to work on 2 as well though this is not recommended. For authenticity a TR5 should have an A type. 

Whether you consider it financially worthwhile is up to you. Certainly a car with OD is more attractive to buyers than one without. 

[elclem1]

Hi Malcolm,  My 5 has an overdrive box fitted 'A' type on 2,3 & 4 gears. Clem

[stuart]

Overdrive is always desirable, for a 5 it would be the"A" Type box as stated above. You chassis number would indicate whether the car originally had overdrive with its suffix having an "O" on the end as in CPxxxx O

Stuart.

[TRTOM2498PI]

36 minutes ago, MJK said:

Hi All,

I've had my TR5 since the mid 1990's when it was totally rebuilt and had pretty light use since. During the rebuild (and for reasons I can't recall) might the o/d gearbox been replaced with a 4 speed box? The boot is badged as an o/d car. Whilst the 4 speed box is fine, I am contemplating upgrading it to an o/d unit.

Is it worth it? Financially and practically.

I am getting conflicting comments on how many gears should have o/d. Internet research suggests gears 2,3 and 4 but ORS in Sheffield have said only gears 3 and 4. Can I seek views on which is correct please.

My main objective is authenticity and whether it's worth doing. I would describe the overall condition of the car currently as in very good condition so I don't think it would be investing in a rust bucket.

Many thanks for your thoughts.

Best regards,

Malcolm

 

 

Installing o/d is definitely worth it. It should have an A-Type o/d unit, which operates on 2nd, 3rd & 4th gears. If you are only doing a few hundred miles a year, I would question if you will really get any benefit, but if you're planning on putting some miles on the car, then it is worth the expense.

 

 

Cheers.

[Drewmotty]

This may sound daft but are you sure that you don’t already have an overdrive box that has just never worked? Stranger things have happened. 
Do you have the operating switch in place on the cowl?

[MJK]

Dear All,

Wow, that's some really quick feedback!!!

 

@stuart - the CP number has an 0 suffix, so that's confirmed it should have an o/d gearbox and my distant memories of what happened during the rebuild.

@Drewmotty - there is a switch on the steering column, so that fits with an o/d gearbox. I don't think there's a defunct o/d on the gearbox but will check before ordering anything.

@All - There seems to be unanimity in the number of gears that should have o/d - 2,3 &4. And also, that the car would be more desirable and be more fun to drive with an o/d box.

Any further comments are welcome but I'll start getting a budget together. From other comments on the forum, ORS in Sheffield gets some good reviews, are there others to consider?

 

Best regards,

 

Malcolm

 

[ntc]

Being a 5 with O it was fitted with a A type overdrive and the relay should be still in the engine bay and definitely I recommend ORS the best imho 

[Malbaby]

Cannot imagine that anyone would fit a non OD gearbox in an OD car.

Although not original, the J type is a more refined OD, and more readily available.

Unless you look under the car, no one would know the difference.

Whether it is worth the cost of the upgrade is another consideration.

[rcreweread]

I'm surprised that ORS advised that OD would only be found on 3rd and 4th, which I assume meant they thought it was a J type box/OD which clearly TR5/250 models never had, the J type coming in on the later TR6s ( CR series I think was the changeover).

Another alternative to consider is Pete Cox (  https://petecoxsportscars.co.uk/  )

Cheers Rich

[MJK]

Following the feedback yesterday, I went back to ORS and spoke with a different person. He advised that the A type o/d unit DOES have o/d on 2,3 & 4 gears - and it's still the same price!!! So, it seems that all the confusion is over. Many thanks to All.

 

Regards Malcolm

[RobertS]

Hello Malcom - I would agree with all of the comments and advice on this thread.  I have a 5 with OD, that operates (surprisingly well) on 2, 3 and 4.  It makes the driving experience much more pleasant.  From a value perspective, I would never buy a TR without OD, so that should hopefully support your decision, but in reality it’s the driving experience which matters.  

On a related point, my gearbox is suffering from “notchy” or “sticky” clutch syndrome.  It’s possibly a broken clutch fork pin, or may be something else.  Does anyone know if ORS would have the expertise to diagnose and fix this problem, or are there other recommendations?  I’m based in the SW, but happy to take the car elsewhere to get the right specialist.  I’m aware it could be an uncertain and possibly expensive fix.  Many thanks in advance.  Rob
 

 

[Dave McDonald]

21 hours ago, rcreweread said:

Another alternative to consider is Pete Cox (  https://petecoxsportscars.co.uk/  )

Cheers Rich

+1 for Pete Cox. 
For a non o/d USA TR6 he supplied me with an A type o/d from a saloon, one of three he had at the time from Mike Papworth, stripped and rebuilt it along with my gearbox all at a reasonable price. He had to change the rear cover plate, solenoid mounting plate and speedo drive to suit the differences between saloon and TR6. 
Definitely worth a try. 
Dave McD

[brenda]

I may be missing something, but if you have the switch on the steering column, have you looked to see if the overdrive is fitted to the gearbox, +1 for Peter Cox.

Mike Redrose Group 

[Andy Moltu]

Stick you head under the car and see if you have an overdrive unit at the rear of the box.

It may answer your question as to whether the overdrive box was removed or if the unit isn’t working.

[RogerH]

2 minutes ago, Andy Moltu said:

Stick you head under the car and see if you have an overdrive unit at the rear of the box.

It may answer your question as to whether the overdrive box was removed or if the unit isn’t working.

Look for a 3" dia BRASS nut - this is the OD filter but.

 

Roger

[stuart]

16 hours ago, RobertS said:

 

On a related point, my gearbox is suffering from “notchy” or “sticky” clutch syndrome.  It’s possibly a broken clutch fork pin, or may be something else.  Does anyone know if ORS would have the expertise to diagnose and fix this problem, or are there other recommendations?  I’m based in the SW, but happy to take the car elsewhere to get the right specialist.  I’m aware it could be an uncertain and possibly expensive fix.  Many thanks in advance.  Rob
 

 

Have you checked to see if the correct dowel bolts have been fitted? Where in the SW are you?

Stuart.

[RogerH]

3 hours ago, stuart said:

Have you checked to see if the correct dowel bolts have been fitted? Where in the SW are you?

Stuart.

Hi  Robert,

 look here #117   2 x dowel bolts       HERE  

 

Roger

[RobertS]

Hi Roger and Stuart - many thanks for that, no haven’t checked those.  Have you had experience of the wrong bolts causing similar issues?  I’m based in Bath.  

[MJK]

Thanks very much for the ongoing feedback and in particular I note the comments re Pete Cox. So he is someone I will speak with. As regards a non working o/d unit lurking underneath, I don't think that's the case as I can vaguely remember a conversation during the rebuild when I was persuaded to accept a 4 speed gearbox solution and forego the o/d until later as a cost expedient.

In hindsight, probably a bad decision. However, I will double check there is no o/d unit attached before doing anything. As you probably know, the existing gearbox will be the host to a new o/d unit and be removed from the car. It will be obvious before doing something I might regret.

Thanks again,

Malcolm

 

[stuart]

17 hours ago, RobertS said:

Hi Roger and Stuart - many thanks for that, no haven’t checked those.  Have you had experience of the wrong bolts causing similar issues?  I’m based in Bath.  

Yes it will cause the "Ratchet clutch" symptoms The bolts in question are at Twenty to Two on the box to engine, all the rest are 5/16" UNF ( 1/2" Spanner) and the dowel bolts are 3/8"UNF (9/16" Spanner size)

Stuart.

[RobertS]

That’s very helpfu, thanks Stuart, I will take a look

[MJK]

Over the Winter, I took the plunge and went ahead with the installation of an overdrive unit to my TR5. Now, after driving it for about 50 miles, I'm delighted with how it improves the driving experience but want to ask about the best way to use it.

I am told by a friend who has a Healey 3000 (also an A type O/D, I think) that depressing the clutch when operating the O/D switch would be beneficial as it reduces the potential for jerking and stress/wear to the transmission in general. 

Are there the views on the forum as to whether depressing the clutch when changing O/D gearing is advisable or any other tips on looking after the unit with careful use?

All comments appreciated.

Best regards,

 

Malcolm

[Peter V W]

Malcolm, No need to depress clutch when operating O/D.

Peter

[stuart]

2 hours ago, MJK said:

Over the Winter, I took the plunge and went ahead with the installation of an overdrive unit to my TR5. Now, after driving it for about 50 miles, I'm delighted with how it improves the driving experience but want to ask about the best way to use it.

I am told by a friend who has a Healey 3000 (also an A type O/D, I think) that depressing the clutch when operating the O/D switch would be beneficial as it reduces the potential for jerking and stress/wear to the transmission in general. 

Are there the views on the forum as to whether depressing the clutch when changing O/D gearing is advisable or any other tips on looking after the unit with careful use?

All comments appreciated.

Best regards,

 

Malcolm

That sounds a typical Healey owners driving style and explains why when I used to restore them back more than 30 years ago every single overdrive unit need rebuilding.

When changing up into overdrive keep your foot down on the throttle and do not touch the clutch. Same when changing down out of overdrive. Obviously when changing up you need more throttle to cope with higher gear and when changing down you need more revs to maintain the same speed in a lower gear.

Stuart.

Edited April 14 by stuart