Posted: Sat Aug 06, 2016 7:08 pm Post subject: M38 Rebuild Snook TX
I have posted a few times about my rebuild but it was all in the Tech Forum but since we have the Project Forum I thought I would start a thread. I started this project 5 or 6 years ago and have made a lot of progress very slowly. Turned out my tub needed extensive rebuild but after replacing the floor and firewall, both lower cowls, lower cowl supports, rear floor and rebuilding the tool box I have finally got most of the body work done and am ready to start the mechanics. I have painted the tub and frame.
I started with this
Took it apart a little more than this
So now it is time to start mechanical things.
I am now here
_________________ R G Mutchler
M274A5
M-38 MC13312
http://willysmjeeps.com/v2/modules.php?set_albumName=rgmutchler&op=modload&name=gallery&file=index&include=view_album.php
I am now at the point that I am doing some disassembly of the engine and differentials, brakes etc.
At this point I don't know if I will do most of the engine work myself or just take it to a machine shop. I know I intend to get the block boiled and checked. But in talking to machine shops and trying decide on their level of involvement I wanted to see if Wes or some of you that have done the engine rebuild machine shop deal if there were any suggestions about question to ask, things to consider and watch when talking to the Machine Shop folks. I am looking at a couple that are supposed to have experience with these engines and have thought that I would offer copies of the military and civilian manuals. Any suggestions or wisdom that you all can share would be appreciated.
The engine ran good when pulled 5 years ago. It didn't smoke and cranked right up and function properly. It hasn't seized as I have turned it over periodically but I don't know about cylinder wear, cam bearings etc.
My last question is if any of you all know of a vender that carries the timing pointers that bolt to the timing chain cover. My engine doesn't have any marks except of the fly wheel. Once I get one of the pointers I can put timing marks on the front of the engine. _________________ R G Mutchler
M274A5
M-38 MC13312
http://willysmjeeps.com/v2/modules.php?set_albumName=rgmutchler&op=modload&name=gallery&file=index&include=view_album.php
A lot depends on your skills and your personal confidence level. I have no idea if you are a mechanical clutz or guru???
A lot depends on the facilities you have, the tools you have and the special equipment you have access to. Looking at your photos I don't see clean work bench tops with vise and grinder/wire wheel. I don't see a cherry picker, engine stand, or axle stand or floor jacks. I do see a torch set, a fabricated tub rotisouri, a parts cleaner and a gantry.
If you want to decide how much of the engine to do I would evaluate my proficiency with micrometers, dial indicators, stud removers, valve train tools, piston/ring tools, Plasti-Gauge, taps and reamers. Take a hard look at how many of these special tools you actually have in your shop. Without these tools and some relative experience with them I cannot suggest you do your own overhauls on engines, trannies and axle assemblies.
To do good rebuild work you must practice the old "Cleanliness is next to Godliness" addage. Organization, clean work areas, detailed photos during disassembly are the keys to a successful and painless overhaul. Careful storage and marking of all parts is very important. USING THE BOOKS CANNOT BE OVER EMPHASIZED! Good shop lighting is essential to quality work as well.
I rebuilt my first engine, a 54 Chevy 235 six in 1964 as a HS junior. While working the next two years in a heavy service Citgo gas station I rebuilt several more. I started racing in 1965 with small block Chevy v-8's. I was drafted in mid 66 but went in the Air Force. Spent 22 in the Air Force as a heavy jet and Helicopter mechanic and built another dozen engines during that time. Retired from the Air Force in 1989 and am still wrenching on aircraft and jeeps. Over recent years I have sent more and more of the engine rebuild process to the machine shop. I still tear down, do initial inspection and dimension checks. These checks keep me ahead of the machinist. I have the shop hot tank and complete machine work on the block as needed, I send crank and cam grinding to the shop. I have the shop fit pistons to bores on any over boring. Valve & Seat grinding and guides I leave to the shop. I assemble and fit valves, pistons, rings and all bearings at my place. I rebuild my carbs and fuel pumps but anymore I send the electrical out for local overhaul. I rebuild my own distributors and do final engine assembly and run-in myself. I have an aircraft service shop hanger with a complete roll around tool set in it. I have a mobile aircraft servicing Van and trailer with complete rollaround and all needed special tooling and I have a 3 bay garage at home with three rollarounds and about 25 feet of bench work top. I have drill presses, hydraulic press, band saw's AC/DC power supplies, several VOM's, coil testers, capacitor testers, timing lights, & dwell tachs. I have many styles and shapes of pullers and inserters. My point with all of this is to let you visualize my experience and shop equipment so you can see why I am able to take as much of an active role in my engine and component overhauls as I do. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Wes,
I am no where near the professional mechanic that you are but have been at it for about 50 years now. My first engine rebuild was a 291 hemi when I was 15, since then I have done a 325 dodge, a 318 dodge, and most of a 392 hemi until someone wanted the incomplete rebuilt engine more than I did and was willing to pay for it. In the early 90's I restored a 55 Chevy and a 67 Camaro, doing the chevy 6 and the 327. When doing these I have relied on the machine shop to do the valve trains, block boils and some mic work. However I haven't done much major engine work since the early 90's and have no experience at all the with valve in block 4 bangers.
I have most of the tools you mention and have used them.
I also had the advantage on all these builds to use the same machine shop in my hometown that was very competent for work and good answers to questions. Unfortunately they no longer exist.
With all that said I am considering how much involvement I will have in this rebuild or if I will farm it out for convenience and time.
I think the intent of my question was when talking to machine shops questions that I might ask or issues I might speak with them about to help determine their level of expertise and/or knowledge of these engines and special problems associated with rebuilding them.
I had also asked about the source of the timing pointer you show in your photos. I have searched on the various websites for it but haven't found it. I thought if you remembered the source it might save me a lot of phone time calling around trying to find it.
I believe John at Midwest has pointers. I am sure you know these came on the f134. The military answer to the early M38's blind timing hole in the flywheel were punch prick's on the cover and a notch in the pulley. If you already have the notch odds are it won't align with the f134 pointer bracker. The later M38 had raised dimples on the timing cover and a notch in the pulley. If John doesn't have one search using F134 CJ5 in your search words.
Late M38
There are three questions you can ask a rebuilder to see just how familiar he is with the L134.
1-What can we do about worn lifter bores which will result in reduced oil pressure?
If the oversize lifter won't meet the spec the block is scrap.
2-Where are these blocks cracked most often.
At the distributor boss.
3-What choices do I have if the center and aft cam support webs are worn excessively which will result in reduced oil pressure?
Willys/Kaiser said scrap the block. There have been successful attempts at boring them to accept a bearing. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Wes,
Thanks for the questions.
As to the pointer, John would have been one of my first calls. I don't have any marks on the timing cover or the front pulley. I do have a raised bump on the timing cover. I have found the timing marks on the fly wheel and a quick check indicates that correspond with DTC. If I can add a pointer I can mark the pulley. Seems that might be as accurate or maybe more accurate that just using the bump on the timing cover. _________________ R G Mutchler
M274A5
M-38 MC13312
http://willysmjeeps.com/v2/modules.php?set_albumName=rgmutchler&op=modload&name=gallery&file=index&include=view_album.php
The most accurate method is to remove the head and dial in the #1 piston TDC compensating for the wee bit of neutral travel by perfectly splitting the degrees of neutral travel. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
I almost have completed the installation of the front and rear axles and have done the brake lines along the axle housings to the wheel cylinders.
When I got ready to install the rear hubs I found that the left one was cracked. I don't know how many times I handled it and didn't notice the crack, but at least I found it before installing it.
Now to install the dual master cylinder and then rebuild the steering box.
Below is a picture of my water pump. I know it is a replacement or rebuilt pump but I was surprised that the bolt would not clear the pulley to remove the bolt. From what I read in the manual the pulley should be 5 1/4 inches in diameter, which it seems to be. Has anyone else had this issue and did this condition indicate a problem water pump. I need to clean it up but it rotates smoothly and was considering not replacing it.
Happy New Year to All.
Progress has been slow with Thanksgiving and Christmas but what better way to start the New Year than by working on an old jeep.
I have replaced all the tie rod ends and the center tie rod link. When I took the old ones out each had about 3 or 4 threads showing on the tie rod ends/tie rod tube. When putting it all back together it seemed to me that I should screw the tie rod ends all the way into the tubes since I have replaced everything and there is no telling what the proper adjustment should be until I get to aligning the front and rear tires toe in or toe out and the front tire toe in. Prior to tightening everything up I thought I would run my reasoning by the collective wisdom on the forum.
If my reasoning is off here or mis-confused any input would be appreciated.
Joined: May 30, 2014 Posts: 3461 Location: Texas Hill Country
Posted: Sun Jan 01, 2017 3:41 pm Post subject:
Ralph, I'd bet that screwing them in all the way would give you toe in.
Just my guess. A machinist wouldn't stop the threads at the required
minimum, but give you some flexibility.
I measured my takeoffs before disassembly as they did not seem terribly
out by eye. At least it gave me a starting point. With everything rebuilt and
good tires I'll adjust at that point.
Not sure what you are referring to when you say "Center Link". There are two tie rod assemblies and each has two ball joints. Are you referring to the bellcrank assembly?
Just follow the setup instructions in the TM 9-8012 page 269. I would screw the rod ends in to about the average of all four original ends were at. IE make them even say with 3 threads showing on each. Now just follow the steps on page 269 in order.
Be sure you have the drag link inspected and serviced to good condition and remember though it looks symetrical at first it is not. There is a front end and a rear end. Follow the page 269 instructions carefully and pay close attention to steering gear center and drag lind neatral positioning before you start adjusting the tie rod ends. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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