Tire size, bearings & brakes Questions.
 

My 67' M38A1 has NDCC 7.00 x 16 tires....I have an opportunity to buy 4 new 7.50 x 16 NDT tires with rims....will these new tires fit....what is the difference in tire size?

Also, what part number is the front inner/outer wheel bearings & races for this jeep.

Lastly, what are the size in inches for the front/rear brake pads without having to pull the hubs to measure.

Regards,

lesk

Regarding the tires:
7.50 - 16 are half an inch bigger in their nominal width than 7.00 - 16 and as they are 100% profile they are one inch bigger in overall diameter. Therefore slightly less wheelarch clearance (not a problem on Jeeps), slightly higher top speed (handy) and slightly worse braking force (probably not noticeable). They will go straight on to the existing wheels as the hole in both sizes is 16".
Whether the new wheels fit the Jeep depends on the size of the centre hole and the number and pitch circle diameter of the holes for the fixing bolts. Simplest thing is just to try one in place and see if it fits, better to try a front one as sometimes the steering linkage fouls if the offset between the rim and the centre is wrong. It depends what the wheels were designed for.

David

Inner and outer were the same: SKF501349 for the bearing and 501310 for the race. A SKF 21159 seal will also be appropriate.



If the Jeep has not had a good going over for a while, I would suggest doing the upper and lower kingpin bearings while you are at it. A much bigger job, but it makes a world of difference on the steering.

As to oversize tires, guys have been putting oversized tires on Jeeps for the last 75 years. The 7.50 size will not make a big difference, although the brakes on the Cdn2 series are still marginal, especially compared to the brakes on the CDN3 series. I assume you have been looking at the tires from militarytires.ca . Quite frankly, it would not be that much more expensive to order the proper size from a place like summit racing, who offer free shipping to the border, and bring them across yourself.

Tires, bearings & brakes
 

Thanks David & Rob...so 7.50 x 16 are fine...the jeep just recently has had an extra leaf added to each spring pack due to minor sagging....it raised the jeep about 1/2 inch over what it used to be so clearance should not be a problem....34 inches at front floor to bottom of center fender well.

Any idea what size brake shoes (front & rear)a 67' CDN2 would have without first having to tear off everything and measure?

On that note....Rob... I read in a magazine that you can grease the kingpin bearings by removing one or two bearing cap bolts and by using a grease needle attachment. I read that diehard wheelers would drain water from their front axles after a river crossing by removing one bolt from the lower bearing caps. (Four Wheeler 1990's...with pictures)....can this actually be done?

Thanks for responding Rob.....its been a while....hope your summer went well...all the very best for 2019.

lesk

Yes, it can be done exactly as described, however, it won't drain water from your Axles, only from each swivel hub. It won't drain water from your diff (which will most like be mixed now with your diff oil and need drain and change), and nor will it drain water from your wheel bearings or free wheeling hubs (if fitted). The wheel bearings and hubs will generally be fine for water crossings, but the diff can "inhale" water through the diff breather on top as the oil cools as you drive through the water.

Bearings & Brakes....
 

Thanks Tony....the article only mentioned water drainage from the kingpin cap bolts so I assumed that you can open one up and grease the kingpin bearings.

Regards,

lesk

Once maintained, I suppose that method is better than nothing. But if yours have not been done in X amount of years, that little bit is grease is not going to undo the wear on those bearings.



A somewhat quick way to decide if you need the bearings is to lift and support the front axle, remove the tire and tie rod end at the knuckle, and turn the knuckle by hand left to right. If you feel a roughness to the bearings, it is time. The cups normally end up grooved where the rollers sit.



You will need to order a shim kit at the same time as you order the new bearings, and you might as well order the large seal kit for the knuckle at the same time. You will also need a fish scale to set the preload on the bearings.



It is a larger job, but is one of the neglected items to the Jeeps steering system.

Kingpin Bearings
 

Thanks Rob....I think there is about 5000 miles since a full rebuild on the jeep which included new kingpin bearings & races....I just wanted to see if I can maintain the bearings longer if I pumped in fresh synthetic grease via the cap bolts. Last spring when the front tires were off I did swing the knuckle back and forth...it was very smooth. I remove the front axle rear hub/knuckle bolts and squeeze in synthetic grease every 2-3 weeks then lock in the hubs for a while so the grease can be flung all over....I think this helps as well.....not sure though.

Any idea the size of the 67' M38A1 brake shoes?....front axle is labelled as Dana 25.

Regards,

lesk

They should be 9" x 1-3/4. There is the possibility that you can have the older brakes from the 52/53 series of Jeeps, which had anchor pins on the bottom, but most likely you will have the same shoes Jeep used for over a decade. NAPA has them under part number TS40.

The shoes Rob refers to should look like this...

The sets also go by NSN 2530-00-307-8860. Same shoes front and rear.

M38A1 Brakes
 

Thanks Rob and Wayne for the pics....Rob....thanks for the Napa part number....off to do some ordering & shopping.

Regards to both...

lesk

M38A1 Brakes
 

Rob....one more question...I was going to order all the brake parts from a US site until you turn me to the TS40 Napa part for brake shoes.....I just called my local Napa and they have a set for $45.00 CAD....as opposed to $40.00 US on US military parts sites....what a savings!....OK....I am also looking for front & rear wheel cylinders....any idea it Napa carries them and if so....what are their part numbers if you have it on record.

Regards,

lesk

M38A1 kingpins
 

Hit up Jason Ginn about kingpins. My CDN3 had a horribly loose front right. He had the touch to take it apart, inspect and reinstall. You and I probably read the same articles. IMHO, pay someone who knows if you don't know.

Ditto on Rob's advice about brakes. The CDN1 and 2 were never especially good at stopping. The CDN3 has bigger brakes. If you find a junker CDN3, seriously consider swapping out both axles. The ratios are the same.

Napa will have the wheel cylinders and at good prices. I,m in mexico right now working off a tablet, so digging in to napa,s jobber site isn,t going to happen, but if you have your napa dealer look up the cylinders (1 inch and 3\4 inch) for a 1950s Willy's they will be what you want. Even CDN tire carried the smaller ones for about $10 back in the day.

Terry
The best thing about the cdn3 axles besides the brakes are the one piece rear axle shafts. Much stronger and more reliable. However the rear axle is also a different diameter so will require the cdn3 u bolts and bottom plates.

M38A1 brakes
 

Great Rob....thanks.....called Napa as per brake shoes....3 days and delivered to my local Napa...$45 CAD per axle....I will call tomorrow as per wheel cylinders.

Thanks to everyone for their input!

lesk

Wheel Bearing & Wheel cylinder numbers
 

A few posts ago Rob sent me Inner and outer wheel bearing numbers of SKF501349 for the bearing and 501310 for the race for a 67' M38A1. These part numbers are for a Dana 27 axle. I ordered these part numbers from my local Napa and the wheel bearings were huge-they were also marked with "LM" which also indicates a Dana 27 front axle. So, I pulled the front wheel bearings from my 67' M38A1 with a Dana 25 axle (9 inch brakes-Napa part number TS40) as per Rob's earlier post and the wheel bearings were marked as Timken 18590 and the race was marked as 18520.
Also, the wheel cylinders are Napa 16534 (front) and 16535 (rear).

I did this research as I was tired of ordering parts from the US with their brutal exchange and delivery charges and to try and buy locally.
I Hope this info helps somebody source local parts.

Cheers Rob and Wayne for your help.

lesk