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Mud in Starter?

Hi, all, first post.

Last fall my wife and I moved to a house here in Maine that is 1/4 mile back from the road, accessed by a dirt road. Now that the snow is melting and we are getting into mud season, the access road is very muddy and rutted.

Lately my truck (1990 GMC Sierra) has been failing to start from time to time.I did a little research on the Net and discovered that mud in the starter is a common problem to off-roaders and mud runners. What might be the odds of my having some mud in my starter, and if so, can I take it out, take it apart, clean it out, and re-install it? Thanks!

I can’t see how mud would get inside the stater driving down a muddy road.

The starter body itself is complety sealed. And open part of the starter where the starter drive is, is inserted into the bell housing of the transmission protecting that part of the starter from mud.

When I was younger I drove down very muddy logging roads in all kinds of vehicles, and never saw mud get into the starter.

Since your truck is a 1990 year, it may just need a new starter.


The water in the Mississippi river is considered muddy. The suspended solids in puddles can enter the starter and other components and when the water drains out a lot of the solids will remain and can accumulate to jam the brushes, the solenoid and bendix. If you can remove the starter and pull the drive end and the brush end ring to flush it with fresh water and then blow it out you might extend the life considerably. I have seen the problem on a few rare occasions on 4x4 trucks used by the hard core mud crowd and farmers but never on family daily drivers. If you are pushing that much muddy water you might want to keep a close watch on your transmission fluid and axle lube. Water up to the starter is above the seals on those components.

I didn’t see the OP stating anything about trying to cross the Mississippi during the flood season. So I took that out of account.


If the truck has the original starter on it then it’s had a long life. Most would have given up by now considering the down low location and heat; and my gut feeling is that it’s probably just worn out. Personally, even if mud was an issue (which I doubt) I can’t see going to the trouble of taking a well used starter apart and slapping it back together.

If the starter is the problem and if you change it then you should get a package of starter shims because odds are shimming the starter will be needed.

I doubt that mud in the starter is the issue. Normal wear and tear is.

I have had two cars that got mud in their starters. Both of the starters had been under water shortly before they failed. Cleaning them out fixed them.

O.K., thanks, everyone. Guess my (not original) starter is fixing to crap out completely!

It may be almost ready to quit unless it has mud in it. Seriously, the problem could be a bad ground connection due to rust. That causes the battery to be undercharged and the connection to be bad at the same time. On my GMC, the ground to check is right up near the master cylinder. Life aint easy and nothing comes free but that ground is right out in the open. Mine is an 02 so you may have to look for yours.

Since GM starters are shimmed out from the bellhousing wouldn’t that mean they aren’t “completely sealed”. After all, there is no gasket between the housing and starter.

The OP’s starter is 23 years old. Kids born when that starter was made are old enough to drink. I think that any expectation that the cause is other than normal wear is unrealistic.

Time for a new starter.

Most bell housings aren’t completely sealed anyway. Most usually have removeable dust covers that vary in shape or size based on the application. They are not watertight and some even have a drain hole.

As to the starter problem it could be assumed that the starter is due for replacement due to age and wear but the exact symptoms were not spelled out. With no solenoid operation there’s the possibility of a bad neutral switch thrown into the mix but I’m assuming right or wrong that the starter is just getting sluggish.

Maybe it’s Penobscot River mud, Tester.