Replacing Dodge M400 front wheel bearings & brakes

[pinballlarry1]

Sent: 7/25/2007

Work continues on Damien, I dismantled the left side front disc brakes and wheel hub.  Nothing special, looks just like my old '76 Datsun B210 only 4 times larger. Everything looks good, but the brake pads are worn down enough to warrant replacement.  They didn't wear evenly, but have a bit of a slope to them.  Still looking for the hub oil seal, shouldn't be too hard to get.

The dust cap is threaded on, uses a 2 1/4" socket for easy removal.  Big channel lock pliers can grab it if you reach in correctly. Lubrication looks adequate, but I would have packed a lot more grease in here.

In order of disassembly from left, top and bottom caliper retainer plates and screws, threaded dust cap, cotter key, castellated lock nut, thick washer, outer wheel bearing. Remove all these items carefully and pull the hub straight off.

It's pretty heavy and needs a good cleaning. Spindle looks great, no discoloration, damage, or goofy threads.

Inner pad is smaller, outer pad is longer and shows greater and more uneven wear.  I hope these don't cost big $$$ I'll post more photos and part numbers when I finish this weekend.
pinballlarry in San Diego

[DaveVA78Chieftain]

Sent: 7/26/2007

Be sure and check the brake hoses and lines.  The steel lines can rust through.
You most likely have the 12.25" rotor that uses NAPA Brake pad P/N TS7020M (or AE7020M).  MKD87 is the industry standard number for these pads (cross reference number).  Make sure you use crocus cloth on the caliper slides to get the rust off so the calipers will slide easily.  That year M400 chassis would use the power steering pump for power brake assist so make sure the drive belts and power steering hoses are in good shape.  Insist on big brand name bearings and seals.  Don't use off brand ones as some people here have already had some fail (lighter construction).  Rotor can be turned but must be replaced if thickness is 1.485". 
Make sure you follow the hub tightening info in the chassis manual under the front axle section.
Dave

[Lefty]

Sent: 7/26/2007

Improper or uneven pad wear is usually caused by inadequate lubrication of the caliper pins and slides. Use high-temp caliper grease on the pins and also where the two halves make contact when the operate.
To me, the outer bearing looks awfully dry, you shouldn't be able to see those rollers so well. I pack as much into my roller cages as I can, insert the rear bearing and seal, then slide the unit onto the spindle. Then I pretty much fill the interior with grease, by the finger full, until the outer bearing squeezes out the excess when installed. Pack the outer bearing well, then install the cap empty. This will allow a bit of space for expansion when the grease gets hot. I've never had a failure on any bearing I packed this way myself. Too much, and the inner seal will rupture when the grease gets hot and tries to expand, throwing grease everywhere.
This is one area where my disability is actually an advantage, my right arm ends at the elbow, and the nub is perfectly shaped and sized to fit over a bearing without covering the rollers. Fill the inside with grease and holding in my left palm,then squish, the grease gets forced right through the rollers and comes out evenly all the way around the cage. Perfectly packed every time 

[pinballlarry1]

Sent: 7/28/2007

Driver's side is done, passengers side ready to assemble.  Even by starting at 7am I have to quit by 9am or I'll be cooked by our wonderful San Diego sun.  I burn very easily being of Scandinavian and European descent.

Timken tapered roller bearings, the good stuff.  Outer #14116, inner #25590. Mine are in good condition, cleaned up and reused.  OOOPS, forgot to get a picture of the inner oil seal, its a Chicago Rawhide/SKF #24459, cost $14 at NAPA, in stock.

Left side reassembled.  New disc brake pads from NAPA, #AE-7020M, in stock on the shelf at $76, no core charge. Probably the most expensive pads I've ever bought, but of course this is the largest vehicle I've ever owned. Inner pad is smaller and hidden behind all that iron.

The passengers side brake pads had worn down evenly, but they were very close the to rivet heads so I feel better now.  I didn't have the rotors turned, they are rusty but the friction surface is not grooved or scored. Brake hoses are in good condition, they appear to have been replaced once.
I plan to finish this project by tomorrow and test drive on the freeway up and down some hills.
pinballlarry

[pinballlarry1]

Sent: 8/1/2007

I just lost 2 days working on the motorhome, had one wisdom tooth removed Monday afternoon. Endured a weekend of sudden pain, now enduring several days of eating mashed potatoes and apple sauce. Not really very hungry yet, but I miss chewing.  Have lost almost 10!! pounds though.  Took Damien for a short parking lot ride today, everything looks, sounds and feels great with the front tires and brakes. My next big hurdle it to drive to the gas station and find out how many gallons the single tank really holds. Even at $2.89 it will be an adventure.
pinballlarry loving his Vicodin tonight.

[77Brave]

Looks like an older thread here but appears to have some info that might be useful to me. Today I am hoping to investigate what is going on behind the front tires. Last weekend I tried to do it but could not even break the seal on the lug nuts. My son had to find a 1 1/8" socket and used his impact wrench to break the seal. Today I'm planning to jack 'Clark' up and take his front tires off. I see this thread is concerned with the M-400. 'Clark' is a M-300: does anybody think the parts would be different?

[DaveVA78Chieftain]

While the design is similar, the parts are not interchangeable between M300 and M400.
You can find all the p/n information for the brakes on my website.

Dave

[77Brave]

Dave,

Thanks for the info and for tuning me in to your website: what a valuable resource and I've got it bookmarked! Well, didn't get to the wheel bearings this weekend: it was just to dang hot. I got in my truck yesterday and it said 126f - for real. I did manage to get to a junk yard and found some miscellaneous parts and some very needed parts for the steering column that got destroyed somewhere along the way. But, that's a different story. Thanks again!

[77Brave]

While my 1977 Brave is not on the M400 Chassis, I think I'd rather report my findings here then start a new thread.

First off, I think everybody should check their RV's lug nuts. I'm a strong, healthy individual and I could not get those darn thing loose for the life of me - even using a cheater bar (which is something I think every RV owner should have on-board somewhere). It would have been awful to take 'Clark' out for a trip, get a flat in the middle of nowhere or even smack dab in the center of someplace and not be able to get the tire off. I was lucky my son has an air compressor and an impact wrench! The lug nuts take a 1 1/8" socket.

I have a 6 ton bottle neck jack. I used two 6 ton jack stands and two 3 ton jack stands: I was super nervous about being inside the wheel well with the tire off. The brake caliper assembly was on so tight that once again, I had to use a cheater bar to get enough leverage to break the seal. The two bolts for the caliper are 15/16". While I was working on the starboard side, I put some penetrating oil on the port side bolts. I'm pretty sure we all know not to let the brake caliper assembly hang from the brake hose. It rests nicely on the upper ball-joint/suspension area. Or, you can tie it up with wire or string.

The wheel hub was larger then I expected. To remove the spindle, it requires a 1 1/2" socket. I couldn't find a spindle wrench of that size but the 'Great Necks' socket I bought worked perfectly.

I did all this primarily to see what the condition of everything was in as there was no real record of prior work. The brake pads seemed thick and new and there were traces of fresh grease inside the wheel bearings and hub. So, I only added a touch of new grease and put it all back together satisfied it would work properly. Today I'll take it out for it's first real road test.

[DaveVA78Chieftain]

Cheater bar?
3/4 Drive socket set with T-Bar handle (flea market tool brand works fine) plus a 4ft long galvanized pipe (I carry this in rig at all times)
For 17.5" inch coined rims, it's 325ftlbs of Torque
Thats 325ftlbs at 1ft distance from lugnut center
162ftlbs at 2ft distance.
81ftlbs at 3ft distance
40-41ftlbs at the end of a 4ft long cheater bar.
You will have to break loose or final tighten with the wheel on the ground (before raising) to keep it from rotating.  If you ever have to replace a disk rotor, take the hub/rotor to a garage that has heavy duty impact tools and a strong vice.

Of course, when loosing any of this stuff, you have to add in the rust factor 

Rear wheel drum will require finding a special wheel hub socket.  It's not real tight (torque) but there is very little room so the thin socket is required.  They are out there at Auto Supplies like NAPA or ones that also support heavier trucks.  Even the Carlisle tool brand has them if memory serves correctly.

Most of your Winne's weight is located on the rear wheels.  Front is not that scary.  Rear though, I hate jacking up the rear.  I have a GVW of 12000 or 6 tons.  I bought a 3 ton floor jack which makes life much easier and safer.  Combined with 3 ton floor jacks it's more than adequate.  Still, I hate jacking up that rear end and placing the stands in place.  Always use a 2x12 board under the stand on asphalt or dirt.  And last, but in no way least, use wheel chocks.

Dave

[DaveVA78Chieftain]

Not sure where you got all your information but the reference documentation says you have a 79 not  78 Winnebago.  78 does not list WDN26RB.
WDN26RB - 79 Rear Bath, 26' Chieftain
http://www.winnebagoind.com/products/previous-models/1979/pdfs/winnebago/79-Chieftain-bro.pdf  Model listed at bottom of the page.
Some of the body parts can be found via the following link: http://www.winnebagoind.com/service/webcd.htm   Winnebago doesn't provide much for your model.

Dodge VIN - M40CA9T5191667 (6th digit is chassis year; in your case 79) which would also make it a 79 model
http://www.classicwinnebagos.com/forum/tech_resources/VIN_decoders/DodgeVINdecoder.html  Google ad bar can cover up the link on the home page.

At top of any site page, select store and follow link to manuals.  You need the 78-82 version of the service manual for your rig.  The 77 parts manual contains most of the parts for your 79 chassis but there are later model parts manuals available.

Dave

[DaveVA78Chieftain]

Dodge Chassis and Parts Manuals are only available via the CW Store
http://www.classicwinnebagos.com/forum/index.php?action=store;cat=42

[JCMAC]

Let's correct that torque(s)
FRONTS: 5/8"-20 studs w/5 studs with coned nuts = 200 ft-lbs, OR 100# at a 2' radius or lever arm, OR 50# at 4'.
                                                       flanged nuts = 325 ft-lbs, OR 162# at a 3' radius, OR 108# at a 3' radius.

[DaveVA78Chieftain]

Yes, you are correct that some correction is in order

Basic Torque Formula: T (torque) = L (length) x F (force)

325 ft-lbs of torque = 1ft bar x 325 lbs of force
325 ft-lbs of torque = 2ft bar x 162 lbs of force
325 ft-lbs of torque = 3ft bar x 108 lbs of force
325 ft-lbs of torque = 4ft bar x 81 lbs of force




400 ft-lbs of torque = 1ft bar x 400 lbs of force
400 ft-lbs of torque = 2ft bar x 200 lbs of force
400 ft-lbs of torque = 3ft bar x 133 lbs of force
400 ft-lbs of torque = 4ft bar x 100 lbs of force

200 ft-lbs of torque = 1ft bar x 200 lbs of force
200 ft-lbs of torque = 2ft bar x 100 lbs of force
200 ft-lbs of torque = 3ft bar x 66 lbs of force
200 ft-lbs of torque = 4ft bar x 50 lbs of force

Or, to look at this another way
If you have a 4ft bar, how much force do you need to apply at 4ft from the nut center to achieve 325 ft-lbs of torque?

325 ft-lbs of torque / 4ft bar = 81 lbs of force

Thanks for catching that

Dave

[Mrfremo]

I know this  is an old post but I am hoping someone might know the answer.  All the manuals tell me that for the m400, the wheel nut torque is 325 ft/lbs, but none of the manuals state what the torque is for the 8 bolts that hold the rotor to the hub (this is for m-400/rm-350 2 piece rotor/hub style disc)