• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)

TR2/3/3A OD in my TR3.

Share this page

doc50

doc50

Jedi Trainee
Offline
Adding OD unit which was not there OEM.
Problem is, the speedo outlet at the lower right side of the OD unit does NOT exit in a direction that allows me to install the trans tunnel without some serious mods to the tunnel.
Is there a 90 degree adapter that I can get so as to aim the outlet downward or forward so that this will all fit?
If needed, I'll try to post a pic.
Thanks,
Thom
TS34909L (O)
 
Yes, you can use an angle adapter from a later car. But it shouldn't be required. The OD speedo cable exits through the side of the tunnel, in the arch that gets covered up by the handbrake boot, and then down through the floor in the same hole as the handbrake lever.



PS, I added the black rubber over the speedo cable, to help protect it. I have a 4 synchro TR6 gearbox, so the cable sits just a little farther to the rear than it would with a proper 3-synchro box.
 
By way of contrast, this photo shows the cable routing when using an angle drive:

ODAngleDrive_zpsb2895a9b.jpg


That's a TR4 but same basic set-up.

I'm not sure why TR4s seemed to use the angle drive as (I think) they have the same handbrake boot as the TR3A but when I got my OD the install kit included an angle drive so I used it.

Of course w/o the angle drive you'll need the longer cable (96"?) whereas with the angle drive the original cable (66"?) can be reused.
 
TR3driver said:
Yes, you can use an angle adapter from a later car. But it shouldn't be required. The OD speedo cable exits through the side of the tunnel, in the arch that gets covered up by the handbrake boot, and then down through the floor in the same hole as the handbrake lever.



PS, I added the black rubber over the speedo cable, to help protect it. I have a 4 synchro TR6 gearbox, so the cable sits just a little farther to the rear than it would with a proper 3-synchro box.
Click to expand...

I had to bend the rear side and top of the trans tunnel ebrake boot cutout after the new tr3b trans w/od moved the drive back..I rolled the edge out in place with a pliers.This gave more clearance and eliminated the sharp edge,all hidden under the boot.
Tom
 
FWIW, the TR4 factory parts catalog lists the 96" cable instead of the angle drive. The angle drive doesn't appear to have been fitted until the TR4A, which had a completely different handbrake arrangement and thus lacked the passage through the boot.

Personally, I prefer the long cable arrangement, as it has never given me any trouble. The angle drives, by contrast, seem fragile, expensive and prone to failure. For example, when I bought Stag #2, one of the selling points was that the angle drive had just been replaced (not an easy task on a Stag). It lasted less than 100 miles.
 
I agree that the angle drive is an additional risk & expense. If mine ever fails on the TR4 I will probably just get a long cable.

Just this week I had the speedo on my E-Type freeze up -- the cable didn't break though, the angle drive 'saved' it by breaking instead. Pulling up the carpet, it was apparent that this was not the first time it had happened as someone (with a hatchet?) had made a hole to allow change of the angle drive w/o removing lots of the interior:

TunnelHole1_zps56beec9b.jpg


I cleaned up that ugly mess and installed a plate over the hole:

TunnelHole2_zps354035c7.jpg


TunnelHole5_zpsae4ca707.jpg


There I had little choice but no doubt a cable straight from the speedo drive is the simpler & cheaper approach.
 
I put an o/d in a 56 TR3 recently, used a TR4 synch box. I routed it out like Geo and used the short cable. The 90 gearboxes are a pain but I usually can rebuild one.

Marv
 
I will try to post up a pic of the clearance problem I am addressing in my TR3. I actually ordered an angle drive (Moss) because I just can't see any way for the speedo outlet from the OD to clear the floorboards without it.

I will attempt to get the pic / solution posted soon. Thanks, all!
Thom
 
PHP:

John, that is a solution I did not consider! It's not stock..but it sure works.
2 shots here of the clearance problem (similar to your issue). Even with the 90 degree adapter I will have to fab a special nacelle to house the out-pouching of the adapter to make the cable snake forward.
Thom
 

Attachments

  • Speed outlet...no room!.jpg
    Speed outlet...no room!.jpg
    60.5 KB · Views: 87
  • speedo outlet, needs 90 angle.jpg
    speedo outlet, needs 90 angle.jpg
    57.5 KB · Views: 85
John, looking closer at your pic...do you have an OEM trans?
Mine is a TR4 trans which adds 3/4 - 1 inch.
Thom
 
I now see your problem...your drive is farther back than the OEM location.

I wonder if the rubber boot can be made to stretch back that far? Otherwise, perhaps 2 one inch holes and use the standard 1 inch grommets used to run the cable through the front firewall. One hole in the tunnel and the second in the floor?
 
P1010735.jpgP1010736.jpgP1010737.jpgHere are 3 pix of the 'final solution'...which, to my infinite surprise and amazement....solved itself with no modifications, blood, sweat or toil by me.....
The cable is, however, routed along the medial side of the vertical floor flange that forms the right side of the trans cover flange.
Turns out that I could have just run the cable in the narrow end of the e-brake hole, as everybody here already knew about....Geez....I ...am....slow.....
Thom
TS34909L(O)
 
Back
Top