Distributor bolt

Mjfire1949 · Post by **Mjfire1949** » Mon Jun 16, 2014 9:27 am

Hey Wes. I need to loosen the adjustment bolt on the distributor to advance the timing on my M38 after a carburator switch. I'm having trouble getting a wrench on it without removing the starter, which would defeat the point of what I'm trying to do ( advance the timing). Is there a special tool or wrench for this purpose. By the way, my fuel pump doesn't have the hand primer. Thanks for your help on that matter.

RICKG · Post by **RICKG** » Mon Jun 16, 2014 9:40 am

Here's a generic distributor wrench, nuthin fancy. Available @ just about
any tool outlet..

buzzk · Post by **buzzk** » Mon Jun 16, 2014 10:31 am

be carefull you don't weild the wrench to the starter disconnet the battery buzz

Mjfire1949 · Post by **Mjfire1949** » Mon Jun 16, 2014 12:00 pm

Thanks for the info. I have already learned the hard way about disconnecting the batteries. Off to Harbor Freight.

Post by **wesk** » Mon Jun 16, 2014 5:21 pm

A set of shorty wrenches should be in your tool box as well.

Don't waste your time with the rediculous timing by the ear thing. You don't have to run the engine to set the timing. It helps to have the engine running and a timing light to confirm you set it right and the centrifugal advance works correctly.

I posted this just a couple weeks ago.

Once you determine weather or not that oil pump turns with the engine you should use these standard steps to prepare for installing the distributor.

1-Clean, lube and inspect the distributor and then make the necessary adjustments using the proper TM 9-1825B found on our downloads page.

2-Clean, the distributor hold/down plate (adjusting plate) and the bolt threads on both bolts.

3-Wire brush the contact surface of the block and the bore of the distributor mounting area/hole clean.

4-Put a light coat of anti-seize on the lower area of the distributor housing that enters the adjusting/holdown plate and the block.

5-Install the adjusting plate on the distributor but only tighten the bolt finger tight.

6-With the engine top center on compression on #1 cylinder (verified by holding your thumb over # 1 plug hole whilst turning the engine by hand in it's normal rotation direction and then verifying that the Timing marks are very close to TDC) Confirm the oil pump shaft slot is indexed properly per the the illustration:

If it is not then the pump must be removed and re-installed correctly.

7-With the distributor in your right hand and your left fingers grasping the rotor insure the rotor points to the #1 plug wire position

8-Install the distributor slowly. When the tip of the distributor shaft hits the top of the oil pump shaft you may have to rotate the rotor very slightly left right until the slots match and the distributor drops the last 1/4" into position and sits firmly against the block. Confirm the rotor still points to the #1 plug position.

9-Before you forget it install the bolt through the adjusting plate and into the block and tighten it.

10-Now align the 5 degree BTDC (Ign) mark up with the pointer or the center of the timing window for early M38's. This should only necessitate a very slight rotation of the crank about 5 degrees.

Early M38's

Later M38's

If you have the M38A1 timing tab.

11-Now remove the rotor and rotate the distributor housing as far as it will go CCW in the retard direction.

Open the points and insert a small piece of clean paper between the contacts and let the points close.

12-Now very slowly rotate the distributor housing clockwise (towards the advanced direction) while maintain a very light pulling pressure on the piece of paper/ The instant the paper slips out of the contacts stop and while holding the distributor firmly still tighten the adjusting plate bolt under the distributor housing. Your timing is now set at 5 Deg's BTDC. No timing light needed unless you just want to check the accuracy of your setting.

M606BR · Post by **M606BR** » Mon Jun 16, 2014 8:38 pm

Wes,

By reading your post I noted that my distributor spark plug cables are indexed differently. Spark plug cable #1 points to 4 o'clock instead of 7 o'clock. Does it mean that my oil pump must be removed and re-installed correctly? If so, how to do that? Is there any tutorial available?

Thanks,

Post by **wesk** » Mon Jun 16, 2014 9:30 pm

The appropriate manual exerpts are in the downloads section. If you search willysmjeeps using google and ask for "willysmjeeps m38a1 distributor " you can review these same questions asked many times before with their rather long answers.

The only real problem with all these improperly indexed distributors and oil pumps is the often times inability to rotate the distributor body enough to set it to the correct timing. If you can get her set to between 5 and 8 Deg's BTDC you should be able to make do with the current indexing you have.