E 350 V Belt Issue

divemaster5734

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The '90 NA 7.3 E350 I'm working on was missing the alternator belt when I got it.
I got a ribbed one for that, and the AC belt that was seriously worn.
I know I had decent tension on all the belts and they were all seated correctly.
The alt, PS, and AC belts all go over both crank and cam pulleys, and air is driven by alt.
Started it up, everything appeared to be running smooth, good current, (22 amps immediately after start up), and the brake assist operating.
Drove it about 1 1/2 miles, ( that's around the block here, a couple short steep grades and tight twisty turns), got home and then this.
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The alt belt was flipped over and the vac belt riding wild.
All belts still have good tension.
( ignore the cable coming from the oil dipstick tube, I haven't gotten around to calibrating the replacement one yet)
Then down at the pulleys
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The alt belt was impossibly twisted around, and if you look closely there something snaking around on the left bottom, that's what's left of the AC belt that snapped.
The air belt was there before, and is ribbed.
The PS belt was the only one still in place, is a non-ribbed belt.
I did replace the alternator with one from the 7.3 donor for the C350 project, but it was an exact replacement, and the charging system was working.
I used the same tension procedure on the e350 that I did on the C350, and the belts on that work perfectly.
Any insight would be appreciated.
Thanks
 

IDIBRONCO

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I can say that the vacuum pump belt didn't stay on the pulley for very long. The groove is still pretty rusty. Are you absolutely certain that there wasn't anything hiding down inside one of the grooves? Like a piece of broken belt.
 

divemaster5734

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Definitely.
That said, I was thinking about wire brushing the pullies.
I reset all the belts after posting, and made sure everything was tight, and promptly snapped the alt belt around the block. I got as sideways as possible at idle and they all looked straight before leaving.
I found a smooth belt in the bone pile that fit.
Put it on and it seems to be working, at least it made the block and held.
I'm using a 2' pry tool to tension the alt as it doesn't have a key like the AC or vacuum.
By the time I made it back there was a belt squeal.
The PS has a turnbuckle to tension that some mechanic put on in the 15 years it was in U Haul service.
I like it so much am going to try to figure out one for the alt.
Have had my share of abuse for the day.
Will have at it again tomorrow.
 

Cant Write

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I fought V-belts in high school almost 30 years ago, what ended up being the problem was someone used the wrong damper pulley, it looked aligned, but as soon as I went over 4K rpm’s the alt belt would throw.(Sbc) took me 6+ month to figure it out.

I was in a junkyard one day and noticed a different type of damper pulley with just a titch of different spacing. I bought it and solved all my problems.

Hopefully you get it figured out, I’m not sure if the IDI’s had different V-belt pulley spacing or not. Good luck!
 

Cubey

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The PS has a turnbuckle to tension that some mechanic put on in the 15 years it was in U Haul service.
I like it so much am going to try to figure out one for the alt.

Heim joint tensioner, available in many lengths. Just an example:

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How it would be used. For IDI, you'd get rid of the quarter circle, slotted tensioner piece on the bracket.

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divemaster5734

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Heim joint tensioner, available in many lengths. Just an example:

How it would be used. For IDI, you'd get rid of the quarter circle, slotted tensioner piece on the bracket.
This one is a much simpler version.
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Here it is loose, the belt can be easily removed.
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Here it is wrench tight, literally as tight, or perhaps tighter than had I used the 2' pry tool to tension.
After trying multiple wrenches a small screwdriver worked best.
Looking at these pics from yesterday I can see that white wear mark on the inside of the belt that I hadn't noticed before.
I'll wire brush the cam and crank pulleys today.
Thinking there's some rust buildup causing the problems.
There was one owner between myself and U Haul, who had good intentions but wasn't very sharp.
I'm not going to start listing the insanely bonehead things they did that cursed their commercial endeavor before it even started, unless I have to replace the entire dash.
In which case this forum will hear about it..
 

Cubey

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A regular turnbuckle isn't as tough, it might break under engine vibration and load variations
 

divemaster5734

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I agree. Was pretty amazed finding it, and just realized the jury rig could be the root of the issue I'm having.
Will probably wind up pulling the fan and clocking all the pulleys before this is done.
On another note, I just ordered two heim joint rods, one to replace the PS and the other for the alt.
 

Cubey

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I agree. Was pretty amazed finding it, and just realized the jury rig could be the root of the issue I'm having. On another note, I just ordered two heim joint rods, one to replace the PS and the other for the alt.

Yep could be. Better off with strong parts. Last thing you want is a broken turnbuckle and loose belts flying into the fan.
 

The_Josh_Bear

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That's some crazy belt action going on. Dang!
I assume you're tightening the alt first and the vac pump second, right? If you do it backwards you'll get the results you're getting to some degree or another.
Oh and the vac pump turns correctly? It doesn't have abnormal resistance, does it?

@Cubey very cool heim joint tensioners, those are sweet! If I had to tighten my belts more that once every few years I'd be on those so fast.
 

divemaster5734

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Oh and the vac pump turns correctly? It doesn't have abnormal resistance, does it?

Don't know what "abnormal" resistance is, can feel a slight resistance when turning by hand, but it is pumping air, and the brake assist works very well, like the difference between power steering and none.
The difference between working on my C350 and E350 is crazy.
I can see why they did the mod.
The AC has a 1/2" key to tension, and it's mashed oval pretty bad.
Even using a 30" pry tool between the alt and alt slide bracket bolt hex nut I wasn't pleased with the tension, compared to the performance of that jury rig.
Not much room to access the lower accessory brackets on the E series, the ps tension bolt hole is a full arm's reach into a black hole with limited accessibility due to the condensed space and hood so low, compared to the F series, where you could just climb inside if you felt like it.
Spent around 25-30 years sitting on the cross member/radiator or fenders on all the F series trucks I owned before getting a Topside Creeper, but then, I don't have to grab a jack to get under my truck.
What's heinous is the way they hide the electronics behind batteries and body parts.
Do enjoy the transmission and gp access though.
Far prefer the F trade-off's.
 

Old Goat

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Your picture of the Alternator in post#1, loosen the bolt
on the slotted arm on top. Use a big Crescent wrench on
the block, and pull on it to tighten the Alternator.
May need to loosen the lower bolt.


Goat
 

Cubey

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clakelaw

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I have a 92 E350 with this same setup. Belts are ALWAYS a problem on this engine. The only thing that works for me is using the Green Gates heavy duty belts. They are thicker and much stronger. The alternator belt gets replaced frequently on mine. I hate that all the other belts have to come off to replace it. Just replaced all mine this week and its about an hour job. The alternator and Power Steering are the same size: Gates 9580HD and the A/C is Gates 9630 HD. The vacuum pump isn't picky but should be tightened after the alt. I use a 1 1/8 wrench on the end top of the alternator and tension the belt. The other way with a bar on the thermostat housing works too. If the pulleys are aligned right, you will like the HD Gates belts much better.
 

divemaster5734

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I put a new belt on the alt and with a weight on the pedal for 1500 rpm popped the hood and the alt belt has a severe wobble between the crank and alt.
I'm guessing these 7.3's turn clockwise.
If no rain today I'll jack it up and get underneath.
The PS belt works, the AC did until I started having issues, but left it off for now, and the vac pump lines up and just quietly does it's job.
Picked up a heim joint bracket but need to mod the mount as just replacing the OEM bracket will cause the blade to hit it.
 
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