New (to me) M1152A1 - Questions!

[matt2491]

So I bought this 2007 M1152A1. It was delivered today. The truck seems to run and drive well (though I've only driven it for about 30 minutes). Everything appears to work and feels tight and responsive.

AM General M1152A1 HMMWV

Bid for the chance to own a AM General M1152A1 HMMWV at auction with Bring a Trailer, the home of the best vintage and classic cars online. Lot #174,570.

bringatrailer.com

A few questions:

1. The tachometer seems to read high. I did some research and it appears to be a common issue with ECV trucks with the 400a alternator. My understanding is I need a different (larger) pulley to correct this? Where can I find the parts needed for this swap?

2. The oil pressure reads as low as 15-20psi when fully warmed up at idle. It goes up a bit when revved. Concern or normal? Engine sounds and feels strong otherwise.

3. What, if any, maintenance should I consider doing as a new owner? I was planning to change the oil and maybe do the portal hubs. Anything else to look at?

 

[BLK HMMWV]

You need to loose the 400 amp alternator.

 

[NDT]

Seller did a pretty decent paint job on it. Oil pressure is fine. I would ask the seller what maintenance he did prior to changing oil etc that might have already been done.

 

[Retiredwarhorses]

No need to replace the 400amp unless you want to just spend more Momey or it fails…changing the solid pulley to the clutching pulley and correct belt will lower “indicated” RPM’s because the pulley is larger, you are going to tach higher no matter what in these ECV’s due to 2 reason, one is that they run 3.08 diffs, the other is a brake switch not adjusted correctly and the torquer converter in no locking up.

 

[matt2491]

Seller did a pretty decent paint job on it. Oil pressure is fine. I would ask the seller what maintenance he did prior to changing oil etc that might have already been done.

I see now in the TMs that the oil pressure can be as low as 10psi at warm idle. Interesting.

The seller said he had done engine oil but not portal hubs. I just asked about the other fluids but have not heard back yet.