MF135 Alternator Conversion

   / MF135 Alternator Conversion #1  

1968 MF135

New member
May 16, 2017
Spalding, Lincolnshire
MF135 1968
Has anyone carried out a dynamo to alternator conversion on an MF135 ?

I'm in the middle of the job and have come against a problem - The original dynamo tensioning arm does not fit with the alternator, it sits on the wrong side of the alternator casting and fouls on the pulley fan. Looks like the "dog-leg" of the arm is too big by about 10mm.

Has anyone else come across this? do I need to get a new tensioning arm made?

   / MF135 Alternator Conversion #2  
In fact almost EVERYONE encounters this. Alternators just don't "slip on" where a generator came from. The vast majority of aftermarket conversion kits require some sort of modification nearly very time, so you shouldn't feel rained on. I've done plenty and rarely had one go without issue in that regard.

Yes, you will need to find (or make) different parts here and there. Delco style alternator frames don't like the straight slotted tension adjuster brackets. The curved ones always fit better. You also need to confirm the pulley is for the right size belt, and the belt is long enough. The alternator sits farther from the engine and a longer belt is almost always needed. Also stand off to the side and look to see if all the pulleys line up properly. Some "creative adjustment" is often needed moving the alternator forward or backward slightly to make that happen. Failure in this regard will result in early belt wear, slippage, and lead to other problems.
   / MF135 Alternator Conversion #3  
I agree with Harry. I have never seen an alternator upgrade that doesn't require fabrication or modification of the tension arm and/or mounting brackets. A pulley change is often needed too. But in the end it is worth it.
   / MF135 Alternator Conversion
  • Thread Starter
Thanks for all the replies :)

This morning I fabricated a new bracket and everything is good now - Fired up and getting a good charge from the alternator, and the wiring sure looks neater under the dash than the Dynamo loom did!

Thanks again :)