M38a1 Retrofit with Mutt Vac Wiper Motor

Restomod · Post by **Restomod** » Fri Nov 10, 2017 5:28 pm

I've obtained a couple of NOS Vacuum Wiper Motors that have 3 Sets of #'s

Top - 2540-00-6778-1340
Mid - DAAE07-80-C-7993
Lower - A-8/81

I figure the lower one is date of Mfr, so these must be M151 Mutt vacuum wiper motors.

Would the M151 wiper motor be a direct replacement for the M39a1 wiper motors?
If it isn't, what has to be modified to make them fit (new brackets, etc)
Can the original wiper arms be used or do those have to be replaced?

4x4M38 · Post by **4x4M38** » Fri Nov 10, 2017 6:14 pm

Short answer? Yes.

Use the search function. Several posts on how to modify the Mutt
wiper motors. Basically shortening the shaft and outer tube.

4x4M38 · Post by **4x4M38** » Fri Nov 10, 2017 6:24 pm

Here's one by Bretto for his M38.

Note Matt who posted there as well has an A1 he did the mods to:

http://www.willysmjeeps.com/v2/modules. ... 151+wipers

Restomod · Post by **Restomod** » Fri Nov 10, 2017 6:41 pm

Thanks for the link, when I put in searches I didn't get any hits.

4x4M38 · Post by **4x4M38** » Fri Nov 10, 2017 8:24 pm

Be sure and use the search function directly above.

The one at the left does not work as well.

Take care,

Post by **wesk** » Sat Nov 11, 2017 12:14 am

Top - 2540-00-6778-1340
Mid - DAAE07-80-C-7993
Lower - A-8/81

Your NSN has a typo. Only 3 digits in the 3rd group of numbers of a NSN. -678- is correct.

That is a Trico wiper motor PN SK527-16, US Army ORD# 7017830 NSN 2540-00-678-1340 as used on the M151 series.

Important specs are:
THROW ANGLE IN DEG - 135.0
ACTUATING SHAFT END CONNECTION TYPE - SERRATED
ACTUATING SHAFT LENGTH 2.750 INCHES NOMINAL
OUTSIDE DIAMETER 0.250 INCHES NOMINAL
MOUNTING HOLE DIAMETER 0.190 INCHES NOMINAL
MOUNTING HOLE QUANTITY 2
MOUNTING HOLE SPACING 3.625 IN. C TO C
MOUNTING HOLE THREAD SIZE 0.90-24

The Late M38A1 series small paddle Trico S583-1 or ORD# 500844 or NSN 2540-00-262-7576 specs. These are the same as the early M38A1 & M38

THROW ANGLE IN DEG - 130.0
ACTUATING SHAFT END CONNECTION TYPE - THREADED
ACTUATING SHAFT LENGTH 1.703 INCHES NOMINAL
OUTSIDE DIAMETER 0.250 INCHES NOMINAL
MOUNTING HOLE DIAMETER 0.190 INCHES NOMINAL
MOUNTING HOLE QUANTITY 2
MOUNTING HOLE SPACING 3.625 IN. C TO C
MOUNTING HOLE THREAD SIZE 0.190-32

4x4M38 · Post by **4x4M38** » Sat Nov 11, 2017 8:09 am

Looks like the actuating shaft is too short.