DeLorean Alternator Tensioner

by Chris Miles

If you’ve ever had to replace the alternator / water pump belt (or just adjust it,) you know what a pain it is – especially if you’re broken down on the side of the road! So, to make it easier, I have been using a turnbuckle style alternator tensioner. It’s made from parts sourced from McMaster Carr. You don’t need to install this now, but it’s a good idea to have it in your car, so that you can install it the next time you replace the belt. (You SHOULD have a spare belt in the car too – Gates

You’ll be replacing the existing alternator tensioner bracket (DMCT Part#: 110102) with this new tensioner. Here are the parts you’ll need to build this replacement bracket:

  1. Stainless Ball Joint Rod End – MC #59915K23 – You’ll need to order a RIGHT hand threaded one *AND* a LEFT hand threaded one. (
  2. Coupler Rod – MC #8419K12 (
  3. Jam Nuts – McMaster doesn’t sell nuts individually, so you may be better off to source them locally.

Alternator Tensioner |

The coupler accepts a ½ inch open-end wrench. Simply rotate the coupler to extend the tensioner, which pushes the alternator away from the water pump pulley, thus tightening the belt.

DeLorean Alternator Tensioner Parts |

I’ve been using these on both of my DeLoreans for years, and have never had an adjustment problem.

At the time of this writing, the rod ends were about $14 each, and the coupler nut was $18. The jam nuts are probably less than $1 each. For about $50, you can have piece of mind that you can replace your broken or damaged alternator belt on the side of the road quickly and easily.

Installed Alternator Tensioner |