I've noticed lately that when my truck gets warmed up real good, the starter drags. I have good cables, battery, etc. When cold, no issue. This is the original OEM starter on my truck (86 F150 351HO automatic) and I'd like to keep it. I see a kit available from LMC but cannot find where anyone has ever rebuilt one. Actually, there is one on YouTube, but it's lacking. I've reviewed several videos on other starter rebuilds but cannot find a good tutorial, video or written, on this particular starter. I believe it is called a Positive Engagement Starter. Anybody rebuild one of these?

Thanks!

 

Do you have the old style starter like this one? https://www.motortrend.com/how-to/mu...-65-73-starter

 

Karl just rebuilt his as part of the motor swap.
Look for a post by him about motor rebuild or swap or something like that.
I was wrong try this https://www.ford-trucks.com/forums/1...placement.html
Dave ----

 

Duly noted.

 

I noticed a slight typo in your original message, quoted above. I'm pretty sure this is what you meant to say, italics added for emphasis:

"I think I have good cables, battery, etc."

Not trying to bust your chops, but until you test the starter system, you're only guessing. What you have described (starter good when cold, drags when warm) is VERY common. When the engine is warm, compression increases and the starter has to work harder to get the crankshaft spinning at the proper speed. Your starter system (not just the starter itself) may be operating at only partial capacity for reasons still unknown. It has enough oomph (sorry for the technical terms) when demand is low, such as when the engine is cold. But increase the demand (warm engine) and now the starter system falls short.

Ten minutes with a meter and you can conclusively test your complete starter system as described here:

https://www.ford-trucks.com/forums/1...w-starter.html


Even if the whole idea makes your head spin, just hook up the meter as described near the end of post #1 and report your results. This test makes sure the battery can deliver the massive flow of electrons to power the starter, and the cables can deliver said power without any excess restriction.

Make sure your battery is fully charged before any electrical troubleshooting. Please don't skip this important step or you may end up in the weeds.

If the test does pass, your starter is the problem by process of elimination. I do NOT recommend trying to rebuild your existing starter. I had my starter out recently during some other work. Although it had been working fine, I thought I'd freshen it up with new brushes. BIG mistake, as they are very difficult to replace:

https://www.ford-trucks.com/forums/1...placement.html

At the very minimum, you will need to track down the correct style of replacement brushes. See the link above for important details about the terminals for the ground brushes. The set I purchased from Rock Auto was wrong.

You will also need a lathe to clean up the commutator. The brushes are VERY hard, some sort of bronze or similar alloy, not the typical soft carbon. Expect to find the commutator worn quite unevenly. With soft brushes, usually you can just clean up the commutator with emery cloth and be good. Not so with these hard brushes. Nor can you just pop in new brushes on a worn commutator and expect the brushes to seat themselves. These brushes are so tough, it's not going to happen.

To install the new positive brushes, you will need a soldering gun of at least 300 watts. As Al Bundy would say, "That a big 'un!". A quick search on Amazon shows you're looking at $50 minimum, more like $75+. I have a 400 watt gun, and it was barely able to heat up the massive copper coils where you have to attach the brushes. The copper makes a great heat sink, and the 400w could barely keep up.

Do the math. $75 for the proper soldering gun and another $10 for the correct brushes, if you can even find them. I'm not even going to factor in the price for a machine shop to clean up the commutator. Meanwhile, you can get a professionally remanufactured Motorcraft starter delivered to your door for about the same price:

https://www.rockauto.com/en/catalog/...ter+motor,4152


Based on Rockauto's listings, I think you'll want Motorcraft #SA734BRM for your automatic transmission. My '84 took a different part number due to the manual transmission. I found it on Amazon for even less, with free shipping and no core charge. See if this is what you need:




I'd suggest staying away from the newly manufactured starters, especially unknown brands like "Fling Dung" or "Wok Hoam". Most of these new units are Chinese garbage. I'd also suggest avoiding "lifetime guarantee" rebuilds from your local discount chain stores. Most of those are little more than new brushes and fresh paint. I think a quality OEM rebuild is the most reliable and cost-efficient option if you do need to replace your starter. But do test the complete starter system first, as detailed above.

 

Thanks for the input, gentlemen!

Karl, appreciate your input. The battery is new as are all the cables. I am the original owner of this 100k mile truck and the starter is the OEM unit so it's time it had a clean up and look over. I'm thinking that the bushings may be worn in it. I'll know more when I get it out and inspect it. I have all the tools and even a lathe as well. I rebuilt the starter in my daughter's 06 Accord so I have some experience and am going to take a shot at the rebuild. If for some reason I can't rebuild it or it does not go well, I'll be putting a PMGR starter on it. I'll post again on how this goes.

Love the old "Lost In Space" show......favorite show as a kid.

 

Careful there, "new" doesn't always translate as "good". Maybe you installed big beefy cables and this is a moot point. But some of the stuff you can get today, especially the pre-packaged cables, have a small conductor wrapped in thick insulation. They may be adequate for a Honda but act like a long skinny resistor under the load of starting a V8. Meanwhile, you end up scratching your head because the cables are new so therefore they can't be the problem.

My starter (original?) had about 270k miles on it and was still going strong. It gave me zero problems. Even though the faces of the brushes were no longer straight, the commutator was worn to match and everything worked very reliably. There was still plenty of life left in the original brushes. I remember having second thoughts if I should clean it up, etc., but I went ahead anyway. What could possibly go wrong? I found out!

YMMY. But if I had a time machine, I'd go back and stop myself from "fixing" a perfectly good starter. I just don't trust the soldered connection where the new positive brushes are attached. I'd like to come up with a more secure mechanical connection before soldering. With my new time machine, I'd probably also find my younger self and attack me on the way to marrying my first wife. There'd be no reasoning with my younger self, so my only option would be to put myself in the hospital for a few days. Oh, but I digress.