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 Chevy Chassis- What Kind of Trouble are You Seeing
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bwest
Administrator

United States
3820 Posts

Posted - 08/28/2017 :  06:08:48 AM  Show Profile  Reply with Quote
I've got several Chevy B7 chassis in my small fleet. I only have two on the route every day but I'm begining to see some issues pop up lately. Some of them include; steering gear loose, lower steering shaft loose, upper steering shaft plastic collapsible pins broken, 3126 Cat breaking rings. I guess that's about everything I'm having right now that's beyond the regular stuff like wheel sensors getting out of adjustment and the brake light/ audible warning going off every 6 weeks or so. (lol that one has been happening since new on all that I have in the fleet now)

mquiring
Senior Member

79 Posts

Posted - 08/28/2017 :  1:13:37 PM  Show Profile  Visit mquiring's Homepage  Reply with Quote
I still have 4 B7's and I'm seeing the same steering issues as you are. I actually have one in the shop right now changing the seal on the output shaft of the steering gear. I've changed a couple of steering shafts also because of them getting loose. It doesn't seem to matter what I do I cant seem to get them to have that crisp steering like my newer buses. I've never had ring issues but we did just do a HEUI pump on one and last year did injectors on our last 3116. Overall though they are still my favorite bus, they ride nicer than anything else we own.
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Thomasbus24
Administrator

USA
4544 Posts

Posted - 08/29/2017 :  04:30:54 AM  Show Profile  Reply with Quote
I hope you guys don't mind a question, it's a curiousity of mine. I looked at a Chevy bus recently that had a 3126. Noticed that the engine wasn't quite vertical, it leaned a bit. Normal for these or was there an issue there?
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bwest
Administrator

United States
3820 Posts

Posted - 08/31/2017 :  06:45:57 AM  Show Profile  Reply with Quote
quote:
Originally posted by Thomasbus24

I hope you guys don't mind a question, it's a curiousity of mine. I looked at a Chevy bus recently that had a 3126. Noticed that the engine wasn't quite vertical, it leaned a bit. Normal for these or was there an issue there?



Don't mind the question at all. It probably needs mounts. I change them whenever I do an OH. They get quite deteriorated.

mquiring, I too have had HUEI pump problems. Very limited though. (Less of those than rings breaking. I've been very satisfied with this chassis, and I'm not a Chevy guy. lol

Bryan
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Thomasbus24
Administrator

USA
4544 Posts

Posted - 08/31/2017 :  10:08:47 AM  Show Profile  Reply with Quote
Thanks for the info. I bet the engine's top right corner was an inch lower than the left, if not more.
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bwest
Administrator

United States
3820 Posts

Posted - 09/01/2017 :  05:40:52 AM  Show Profile  Reply with Quote
quote:
Originally posted by Thomasbus24

Thanks for the info. I bet the engine's top right corner was an inch lower than the left, if not more.



Yeah, I'd say that's your problem. They are pretty thick mounts. Chevy still has them but when you order one, you only get one (top or bottom of the mount. So, really if your bottom part isn't damaged you won't have to replace it. The bottom doesn't have weight on it anyway.

Bryan
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mquiring
Senior Member

79 Posts

Posted - 09/01/2017 :  06:10:31 AM  Show Profile  Visit mquiring's Homepage  Reply with Quote
I've never looked that close at the mounts on mine. We've never had to pull an engine one one yet. I might have to look a little closer as I do have one that has a funny rattle at idle under your feet.
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bwest
Administrator

United States
3820 Posts

Posted - 09/01/2017 :  10:45:34 AM  Show Profile  Reply with Quote
quote:
Originally posted by mquiring

I've never looked that close at the mounts on mine. We've never had to pull an engine one one yet. I might have to look a little closer as I do have one that has a funny rattle at idle under your feet.



The engine can't go anywhere. There's a locking nut on the bold that goes through there.

Bryan
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baptistbusman1
Senior Member

USA
175 Posts

Posted - 09/01/2017 :  2:13:16 PM  Show Profile  Reply with Quote
Every single Chevy/GM B7's I have had developed steering problems where the steering would intermittently get so stiff you could barely turn the wheel when you were stopped or trying to get out of a tight spot. Changed pressure switches and pumps numerous times with no luck. Ultimately was the nail in the coffin for these buses.

I was formally Baptistbusman. However, I lost my password, and had not updated my email address.

Here is a link to my old posts. http://www.schoolbusfleet.com/forum/search.asp?mode=DoIt&MEMBER_ID=1846
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mquiring
Senior Member

79 Posts

Posted - 09/04/2017 :  6:50:57 PM  Show Profile  Visit mquiring's Homepage  Reply with Quote
I've never had that happen yet. But I have had on every one of mine that had 9R-22.5 tires develop a death wobble so bad that you would have to completely stop to get it to quit. We added steering stabilizers to them and it cured it. My biggest complaint is that I just cant seem to get the steering to be as tight as I'd like no matter what parts we change.
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bwest
Administrator

United States
3820 Posts

Posted - 09/05/2017 :  07:03:33 AM  Show Profile  Reply with Quote
quote:
Originally posted by baptistbusman1

Every single Chevy/GM B7's I have had developed steering problems where the steering would intermittently get so stiff you could barely turn the wheel when you were stopped or trying to get out of a tight spot. Changed pressure switches and pumps numerous times with no luck. Ultimately was the nail in the coffin for these buses.



lol, do you know what the problem was? I chased mine for quite a while. Finally put one out of service it was so bad. I found the u-joint bad on the shaft that hooks to the gearbox. It's one of those simple fixes that runs a guy nuts!

Bryan
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torque
Advanced Member

Canada
358 Posts

Posted - 09/05/2017 :  08:45:21 AM  Show Profile  Reply with Quote
quote:
Originally posted by mquiring

I've never had that happen yet. But I have had on every one of mine that had 9R-22.5 tires develop a death wobble so bad that you would have to completely stop to get it to quit. We added steering stabilizers to them and it cured it. My biggest complaint is that I just cant seem to get the steering to be as tight as I'd like no matter what parts we change.



I have not had one of these for many years, but the last one I had did the same thing only the new steering damper didn't fix it. It might go six months without a problem then out of the blue they would go into a violent shimmy but still steer straight even with your hands off the wheel. The driver would simply pull over and stop, and start driving again without a problem.
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bwest
Administrator

United States
3820 Posts

Posted - 09/17/2018 :  09:48:31 AM  Show Profile  Reply with Quote
Old topic here but I'm wondering if anyone is having issues with three lights coming on on the dash on these B7s. Brake AUX, coolant level and primary brake. There isn't a mechanical issue. This started after I replaced the alternator.

Bryan
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wocobus
Active Member

United States
18 Posts

Posted - 09/18/2018 :  2:21:30 PM  Show Profile  Visit wocobus's Homepage  Reply with Quote
Just a guess I would check and clean all ground straps.
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bwest
Administrator

United States
3820 Posts

Posted - 09/19/2018 :  05:33:23 AM  Show Profile  Reply with Quote
Thanks

Bryan
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mquiring
Senior Member

79 Posts

Posted - 09/19/2018 :  4:51:18 PM  Show Profile  Visit mquiring's Homepage  Reply with Quote
I had the same thing happen a couple of years ago. Turned out the new alternator had a problem. Of course I didn't figure that out until I had wasted a bunch of time chasing connections!
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bwest
Administrator

United States
3820 Posts

Posted - 09/20/2018 :  05:38:11 AM  Show Profile  Reply with Quote
quote:
Originally posted by mquiring

I had the same thing happen a couple of years ago. Turned out the new alternator had a problem. Of course I didn't figure that out until I had wasted a bunch of time chasing connections!



Yeah, I'm thinking alternator too. It's coming back in today to get an emergency window. So, I'll hopefully know soon enough.

Bryan
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