Battery Ground ?

[seadog]

If I ground the battery, which is located in the trunk, to a transmission bellhousing bolt on a tranny with an aluminum case; will there be a problem with corrosion?  It will be much easier and cleaner to ground to the bellhousing as opposed to elsewhere.  Just wondering if the dissimilar metals involved will set up electrolysis.  Thanks.

[UGLY OLDS]

If I ground the battery, which is located in the trunk, to a transmission bellhousing bolt on a tranny with an aluminum case; will there be a problem with corrosion?  It will be much easier and cleaner to ground to the bellhousing as opposed to elsewhere.  Just wondering if the dissimilar metals involved will set up electrolysis.  Thanks.

Use some dilectric (spl?)  grease on the terminal ,then secure the bolt..It wont corrode...



Bob...

[PeterR]

Electrolysis is not the issue, the real potential for damage is rogue currents passing through the transmission and damaging the bearings.

During cranking, the battery is supplying hundreds of amps and it does not take much current weaving its way through the transmission to burn the bearings.

The closer the earth lead is to the starter the better.    Also it is important to run a short cable from the ground point to the body, otherwise the transmission will be the return path for all ignition and lighting loads.

[seadog]

Electrolysis is not the issue, the real potential for damage is rogue currents passing through the transmission and damaging the bearings.

During cranking, the battery is supplying hundreds of amps and it does not take much current weaving its way through the transmission to burn the bearings.

The closer the earth lead is to the starter the better.    Also it is important to run a short cable from the ground point to the body, otherwise the transmission will be the return path for all ignition and lighting loads.

Would it then be alright to ground to a starter bolt instead of the bellhousing?  I'm trying to stay towards the rear of the block.  Thanks.

[Dave]

That should be fine.. I ground all mine with a heavy short lead from one of the fuel pump bolts to the frame and sometimes I just use the motor mount bolt going thru the frame.. seems to work fine..
Dave  

[Crosley.In.AZ]

I have trunk mounted battree on my 62 Falcon sedan... I have a ground from battree  to the chassis (uni-body) , a 10 gauge wire runs up to the trans case from the battree , a braided copper ground wire from engine block to the body shell ( uni-body).

On my 1961 Dodge Lancer 770 with battree in the trunk... I run a ground wire same size as the power cable from the battree up to the engine block. Various ground straps from the engine to the chassis ( uni-body design too)

Both setups function well.

When in doubt... add another ground strap with clean metal at the point of contact.

[enjenjo]

I have grounded to the trans case on several cars with a rear mount battery, as yet it has not caused a problem.

[Dave]

Oh ya i forgot that i grounded the battery fromn the trunk to the frame
Dave

[Learpilot]

I learned from my Dad when I was a know it all teenager about grounds. My dad always ran grounds everywhere. I was having some weird voltage spikes and could not figure it out. He ask me if I had a body ground as well as a ground to the chassis and engine. I said I did not need one. Well He insisted on me adding those grounds and guess what my problems went away.  Now that my  Dad left us in 2007 I sure know how smart he really was. He taught me how to enjoy building Hot Rods and driving them. He built some great Flathead Dragsters (3) and they drove great and won a lot of local races. The best time in 1968 was 11.05 sec at 123.56 mph in a 1/4.

Rick Harris