• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Grounding the gearbox?

Share this page

karls59tr said:
Can this aid in getting a good ground for the starter considering the usual ground locations are secure and clean?
Click to expand...
No.

But if you really want a better connection for starting, run a heavy cable from the negative battery terminal (assuming neg ground) directly to the block. Then add jumpers from the block to the frame and to the body. Running the starting current through the body, as in the original design, is kinda dumb. I'll bet you lose a volt or two at the starter by doing that.

 
I do have the stock fuel pump removed and the hole blocked off. I like your idea about grounding the Neg bat terminal to the bolt that holds that cover on. I believe the TR3 already has a small braided ground strap in the steering box area is there not?
 
Karl
Yes there normally is a ground trap on the left of the engine at the front.
This should connect engine and chassis - bridging the rubber engine mount.
I have connected a stand alone - additional ground strap at the rear from an engine gearbox bolt to the battery ground to body. Effectively direct ground to battery

To be honest you can’t have too many ground wires around the place.
 
My point is to run the cable directly from the battery terminal to the block. That avoids the relatively high resistance of the current path through the chassis. The place where it connects on the block isn't important.
 
Just my 2 bits. On a well maintained car there will be no advantage. However, if you are having grounding issues, running a separate cable from the battery directly to the engine/trans may be much easier than going through hours of trouble shooting.
 
The ground path on the early TR's leaves something to be desired. As originally configured, the battery grounds to the body and the engine grounds to the frame. Bonding of the body to the frame is incidental. That is, there is no discrete conductor (wire). Rather the ground path is through all of the bolts and components that attach to the frame and body like rear fender stays, radiator, speedometer/tachometer cables, etc. I ran into a conductivity issue during reassembly recently. Seems my efforts to ensure the chassis and body were well painted, mounted with new rubber packings and such pretty well insulated the body from the frame. I added an additional ground strap between a bellhousing bolt and the firewall, and all was well. Triumph apparently figured this out over time, look at a TR6 ground cable.
 
My old 59 was grounded so poorly that a black grounding wire to the rear lamps was necessary
for them to work at all. Rust had broken the rear section of the body/frame grounding as most of the
bolts had perished.
Mad dog
 
Back
Top