Help needed to stop me throwing money at my CUCV, Hopping/Vibration

[Ackevor]

Some pics and another concern

Are my axle shaft u joints non serviceable?

A few extra pics to keep things interesting.

 

[Jeepsinker]

No, they are not serviceable. When they go bad you just replace them with greasable ones. You know how to change these right?

Wait, there is a grease fitting on one of those I just saw. So they are servicable, but they are held in with c- clips on the inside face of the ears. They can be hard to see when they are dirty and rusted.
The clips are on the inside edge of the caps facing in toward the cross. May take some digging and scraping with a mechanics pic or small screwdriver to find the edges and ends of them. Once you get the clips off it is just like changing driveshaft u- joints.

 

[cucvrus]

It looks like Mr Rusty all over again. I see you need to make some backing plate tins. i found a set of them in my scrap pile. But I just made a set for another truck last year. i used what you have left there cleaned them up and cut and welded a piece of 14 gauge galvaneal to the remnants. It worked. They are not really needed. It will pass PA inspection with out them. I would sooner they not be there then be there in the condition they are in. I still like my newer trucks better with the sealed hubs. I seem to have less maintenance with them. But they are not 30 years old. It is only going to get worse. It is like a money pit. You just get to the point where you keep it running and passing inspection. Most CUCV's are to far gone for the average owner to do the repairs. I have worked outside in the dirt and still do. With out a garage full of tools the up keep gets to be a major issue. Keep at it. Good Luck.

 

[Ackevor]

Thanks Jeepsinker and Cucvrus. Yes both sides are greasable, and they are good but already bought replacements. I have not replaced u joint with what looks like caps sealed onto the shaft before. Hopefully I can get the clips off and figure it out. With the clips out they will just press out like normal?

I figured the rusted out dust plate is too far gone, ill just end up running without it unless I can get new for relatively cheap.

 

[Ackevor]

Ok answered my own question by looking at the new u joints, I didnt realize they stuck out like that on the ends, I thought it was some kind of pressed in cap.. Heres a few more pics from today.

Bad news though... When I ordered new Calipers from Rockauto, they had a closeout special on a loaded pair for like $50. I thought I lucked out until I finally opened them today and found they are the bolt on ones. Its likely ill have to eat the cost of them as well because I order things when I think I will have time to do it, only to get it pushed back by 2 months. So im at about 90 days. We will see though as they are still in the wrapping.

 

[Ackevor]

Looks Like Rock Auto wants nothing to do with me having the wrong Calipers. They actually told me to sell them somehow... know anyone who needs a pair of loaded Morse calipers for an 80s Chevy?

As far as the drums go, one for sure is out of round, and the other likely needs balanced. I havn't found a place nearby that balances these drums, probably need to find a machine shop to do it. Unless you think it can be done using a static balancer through the center hole? Then I could weld on, or drill out material until its balanced. For the out of round one, Rock auto is only allowing me to replace with the same part... Here is what Pronto claims

Pronto take's pride in their attention to detail and their reputation for outstanding quality. Each Pronto brake drum is designed and engineered in conjunction with globally sourced manufacturing partners. Pronto units are manufactured by ISO certified factories to meet requirements of fit, form and function.
Features

• Engineered to high metallurgical standards to provide consistent quality, strength, performance and reduced noise.
• Precision balanced which guarantees smooth, vibration-free performance
• Ongoing Testing of: Thickness Variation, Run Out, Parallelism and Dimensional Verification ensures that all drums meet dimensional and weight specifications
• Designed to ensure easy installation

If this were true I wouldnt be in this mess. Should have ordered Raybestos I guess.

 

[cucvrus]

That is why I buy new replacement parts locally. I am well known at the Autozone and the other parts houses. When I have an issue I walk in and face to face we get the issue resolved. I may pay a bit more for this and I know that. But I am paying for the service and the respect that I receive during and after the sale. My wife has a newer Chevy Impala and drives it like she is in the Talladega 500. When the brake pads are worn out I walk in to Autozone with the worn out pads and they give me a new set. Granted I must buy a get of rotors they always last longer then the 2 year warranty but that is only $60. for the rotors. $0. for the brakes. And she is back on the road. So I buy it locally at Autozone and the warranty is covered. I never buy appliances at a box store. I don't care if they are cheaper. I look at service during and after the sale. Auto parts are the same way. Just live and learn. Less expensive in most cases is just that. There's a reason to pay more at some times. My opinion and spin on things.

 

[Keith_J]

I am having vibration issue too on my 1031. Shocks are bad but this caused the springs to sag. So I am getting the springs rearched. When I measured the arch by lifting the frame until the rear wheels were off the ground, where it should have been 6.25" of arch (an a bit more with the axle hanging), it was 5-1/2".

Hoping it isn't a broken leaf. That can happen when the U bolts rust out, causing the necked down portion to stretch which loosens the clamping load on the spring stack. Then the spring breaks in the middle where the dowel hole weakens it.

 

[cucvrus]

You ever have any luck with re-arching leaf springs? I never have. It seems they are good for a while and then just return to the low down. I have been replacing the springs from this point on. And the rear saddles are available in cast steel now so I opt to replace them at the same time. Snow plow trucks are hard on springs. The salt spreader tears them up. I have replaced the springs on the spreader M1028A2 and it has been going for 10 + Years. I was seeing the slouch on rearched springs after the second year. I think the steel looses its spring and has been sprung. That has been my experience with these 1 ton trucks on Fords and CUCV's. Even an M1009 gets a better look with a new set of stock height leafs the whole way around. Stock springs or 4 ply up front if you are sporting a plow.

 

[86m1028]

I am having vibration issue too on my 1031. Shocks are bad but this caused the springs to sag. So I am getting the springs rearched. When I measured the arch by lifting the frame until the rear wheels were off the ground, where it should have been 6.25" of arch (an a bit more with the axle hanging), it was 5-1/2".

Hoping it isn't a broken leaf. That can happen when the U bolts rust out, causing the necked down portion to stretch which loosens the clamping load on the spring stack. Then the spring breaks in the middle where the dowel hole weakens it.

Bad shocks will not cause vibrations or springs to sag.
Age & weight is what kills springs.
I have never seen rearching work or last very long.

 

[Keith_J]

Bad shocks will not cause vibrations or springs to sag.
Age & weight is what kills springs.
I have never seen rearching work or last very long.

Not true. The axle+wheels makes for a mass. The spring is, well, a spring. Mass-spring pairs have a natural frequency dictated by the square root of the quotient of the spring constant over mass. Without going into the physics, it is the same as a pendulum's natural frequency. That is the purpose of a shock absorber, to PREVENT oscillation. Some vehicles can get by without shock absorbers as the natural frequency is outside of the range of excitation.

The initial failure mode of a shock absorber is low frequency, this is the mass of the vehicle coupled to the spring. The final failure is higher frequency, the mass of the axle+wheels (unsprung mass) and the spring system. Note, there can be multiple modes of vibration, single wheel, coupled wheels and rotation about the drive shaft.

Now, what causes spring sag? Simple, cycles. Most of the big bump cycles do nothing. It is the higher frequency, lower amplitude cycles which do far more fatigue to the state of the steel. This is where the common (misconception) of spring age due to sag comes from.

Simple rearching without reconditioning is nearly pointless because the friction between the leaves is not addressed. The term here is hysteresis and it is from excessive friction. Full reconditioning with subsequent shot peening after re-arching makes for a permanent process. Shot peening restores the compressive stress in the outer skin of the spring, the most highly stressed portion of the steel.

There, now I am off my Mechanical Engineering soap box. No myth, just facts. The company I selected to re-arch my springs has been doing it since 1935 and still owned by the same family.

 

[infidel got me]

Bad shocks can cause a vibration. I had a ford E-150 van come in a few years ago and the shocks were so bad that the right front tire would leave the road at 60mph. It kind of was a basketball effect. We rotated the tires, put on new shocks, and had a smiling customer. The shocks were toast, the rest of the front end checked out ok. If I didn't work on it myself I probably would not have believed it either.

 

[Ackevor]

That is why I buy new replacement parts locally.

I prefer this as well, but local stores didn't have what I needed in stock so I had to resort to RockAuto. I have had really good experiences with Advance so I prefer to purchase from them... however their inventory has drastically dwindled for the older stuff. They don't even carry basic stuff like rotors and drums anymore for these vehicles. Luckily I talked to the Manager of the one I frequent and he graciously ordered in the parts I needed without the need for payment simply because of the business I have done with them. This means today I get to pick up 2 Calipers (the proper ones) and a set of ceramic pads for $70 only because he is going to honor the TRT41 online code for $40 off $100+ purchase.

I am wondering if my front leaf springs are bad, one of the last picture I posted show them arch a bit.

***Ohh almost forgot!!! when I installed the wheel bearings on passenger side front, I think I installed the oil seal that keeps water from getting into the bearings a little far. Instead of putting it flush with the hub surface like it normally is, I tapped it down to a lip where it stopped which is about 1/8" below flush. I forgot I did this until I pulled the driver side and saw it flush. I do think though, that the seal should still be contacting the proper surface, but its impossible to tell with the splash guard. If I try to move it back out I will simply ruin it.

 

[Ackevor]

Finished installing new:
Front axle U joints on both sides with Moog grease-able units.
New spindle bearings and seals
New wheel bearings and races
New Rotors
New Calipers and Pads
New Hydraulic hoses
One new Brake line passenger side (Removing old line it spun with nut.)

Filled with fluid and bled as best I could myself. Brakes work fine, peddle is a bit squishy but will improve once I get a helper to hold down peddle while I bleed again.

While test driving and breaking in the braking surfaces, I took a hard left turn into a parking lot, I was still slightly on the brakes and I could hear lots of clanking going on. Its hard to replicate and hard to distinguish where its coming from. This happened prior to the new parts as well.

I notice too when at speeds above 45 mph, if I let off the gas suddenly, the truck pulls to the right without braking, almost like torque steer. The pulling hard to the right while braking has ceased, probably due to completely new braking system. However!!! it will pull in whichever direct I may nudge the steering wheel. If I brake hard and nudge it to the left a bit, it wants to pull hard to the left, If I go right a bit, it wants to go hard to the right... Starting to think I might just replace the front steering components as well and get an alignment which is likely needed as it does still hang right on the straights.

 

[militarytrucks.com]

I will suggest that you check the ball joints, and steering gear box. A steering gear box that has the gear clearance set to tight will cause the steering wheel to not want to return back to center.
Also, worn ball joints, or king pins can cause a caster angle problem causing the vehicle to pull to one side or the other. Most vehicles will drift to the right slightly due to design requirements ( if you fall asleep behind the wheel you don't drift into oncoming traffic).

I see in your first post, that you replaced "king pin springs". I am not sure if you meant you replaced the front springs, or front kingpins, but if not I would suggest that you check for broken front springs, spring center pin that is missing or broken on all four spring sets, worn spring hanger bushings. These can all cause erratic steering.

Front Toe can be adjusted with two tape measures to get it close, prior to taking the vehicle to an alignment shop. I try to set a CUCV to 1/64 toe in after steering component repairs, before sending it for an alignment.

 

[cucvrus]

You are missing the small spring clips that go on the axle inner side of the brake pads. Less than $5. to get new ones. I bought 10 for $6.50.

 

[cucvrus]

These a small tin pieces., May i suggest NAPA. they are made in USA at NAPA. I bought them at other places and they broke while putting them on. Check it out. It could also be worn that they will not stay in place. Put 1 clip on top and 1 clip bottom of inner brake pad if possible.

 

[Ackevor]

You are missing the small spring clips that go on the axle inner side of the brake pads. Less than $5. to get new ones. I bought 10 for $6.50.

The new Calipers came with one spring clip for each, but I couldn't figure out how or where it goes on. The old ones didn't have this clip. I tried searching for a reference image or something on here but didn't turn up anything so I left it off.

I will suggest that you check the ball joints, and steering gear box. A steering gear box that has the gear clearance set to tight will cause the steering wheel to not want to return back to center.
Also, worn ball joints, or king pins can cause a caster angle problem causing the vehicle to pull to one side or the other. Most vehicles will drift to the right slightly due to design requirements ( if you fall asleep behind the wheel you don't drift into oncoming traffic)
Check for broken front springs, spring center pin missing or broken on all four spring sets, worn spring hanger bushings. These can all cause erratic steering.

Front Toe can be adjusted with two tape measures to get it close, prior to taking the vehicle to an alignment shop. I try to set a CUCV to 1/64 toe in after steering component repairs, before sending it for an alignment.

I will have to look up how to check the steering gear box, no clue how to adjust what your talking about.

Kingpins are solid, new springs and bushings as well.

The steering components, don't have any play while the truck is off the ground, but it could only be present while the weight of the truck is moving them, I didn't want to mess with the alignment yet as I thought I might replace a few items if they were bad as not to waste any valuable time

As far as the springs go, nothing broken, but now that you mention worn bushings, one of the them looks like it needs replaced... which usually means its time to replace them all. How difficult is it to remove the front leafs and replace the bushings?

 

[cucvrus]

They clip on the bottom ear of the inner brake pad and you compress the spring of the clip and put it in place. That will hold the pad semi tight and keep it from clicking. I have an M1008 that has the groove in the pad holder worn and it still clicks a bit but it has the spring clips in place. You did put the clip / spacer on the slide when you hammer it in? I have to ask. I have seen them without that spacer.

 

[militarytrucks.com]

"How difficult is it to remove the front leafs and replace the bushings?"

Support the vehicle by the frame. Position floor jacks under the front axle. Remove the front spring shackle mounting bolts. Lower the front axle.
Drive the old worn bushings out with a drift, and large hammer. Install new poly bushings per manufacturers instructions. Reverse procedure for installation of springs. repeat the process for the front spring rear bushings.