[Jeff]

Chad, I have a mechanical tensioner on my Radiator Fan gear box, I can send you a picture of mine if you are interested, Basically a tube with one side right hand threaded, and the other left hand threaded. Prevost might have the parts in stock.

[Archived]

If it’s not too much trouble, Mike, that’d be great. I found a number of photos by scouring for sale ads, and there were a few that look like the Prevost drawing without springs. I just noticed that the drawing I posted that includes springs may only have been for models before 1978. I’m not clear on that. I suspect I’d be okay without a spring in the system, but now is the time to figure it out.

I think I can piece something together off the shelf, but Prevost Parts does have some components in stock. I think they have the rod ends for about $25 a piece. I may try to put something together with stainless steel. McMaster-Carr is a bit spendy though.

[Bill]

I will send some pics tomorrow, the sun just went down on the West Coast.

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2005 XL Thompson Coach

Rarely tow anything behind us.

Sold: 1993 Liberty that we loved for 12 years.

[John]

Chad, don’t over think the solution. I used threaded rod, initially from the ends cut off brake chamber to prove the concept, and now stainless steel threaded rods and nuts to make loosening the belts without fighting corrosion.

I do not remember the details about an 8V92, but on the Series 60 I do need just a couple of 15/16 wrenches and in a few minutes i can loosen and remove any belt.

[DON]

Fellas, can you post (or email) pictures for me as well. Thanks, John

[Archived]

Chad’s picture above was what was on m7 ’88 8V92. It is several pieces with left and right hand threads to allow tightening and loosening. There is also a pin at the bottom right of the setup with a cotter pin so you can loosen it up and if the belt is still a bit tight pull the pin, install the belt and reinstall the pin and cotter pin. You might need a 2nd person to help or some kind of pry bar to move it that last 1/4″.

[Jon]

Chad, here is my Tensioner, a tube with left and right hand threads. When you spin the tube one way it makes the dimension shorter, when you spin the tube the other way it makes the distance longer,

[Loc]

Thanks, Mike. Different setup than mine, but that’s the concept. I removed the air tensioner today, so now I just have to get the parts ordered.

[Chad]

Here’s what I came up with. It has plenty of range to give both good belt tension and ample slack for changing belts. I batted around a few ideas to achieve the proper length while retaining maximum adjustment range, and the 6″ turnbuckle rod with 2″ male threads at each end ended up being the key. The female turnbuckle rods weren’t threaded deep enough to suit me.

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1984 96" with 8V92TA

(remodeled Liberty Coach)

Greenwood, MO

[Chad]

I ordered everything from McMaster-Carr. The turnbuckle connecting rod was pretty hard to find, and I eventually had to change from zinc-plated steel to stainless steel due to a back order. That added about $50 to the cost. The total of around $200 was more than I expected, but still worth it. I also ordered some greater quantities of nuts and washers to reduce the per-unit cost, which bumped the total up a bit. This image is just a sample order I created for this post.

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1984 96" with 8V92TA

(remodeled Liberty Coach)

Greenwood, MO

[Chad]

I found that a big pipe wrench works well to pivot the fan assembly up to apply tension to the belts in order to measure the overall distance needed for the tensioner. I took this picture just as a reference after the job was complete. The tensioner obviously wasn’t there yet when I took the measurement. The pipe wrench method is an easy two-person job, and a very awkward solo job. I found it simpler to use a ratchet strap between a bracket on the bus frame above the left rear engine door hinges and the swing arm assembly. That might not be practical for most, but I have my coolant surge tank removed at the moment. Lots of room for me. I didn’t get a picture using the strap.

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1984 96" with 8V92TA

(remodeled Liberty Coach)

Greenwood, MO

[Chad]

The tensioner can be adjusted with a single adjustable wrench, or both 1/2″ and 3/4″ open ended wrenches. As long as the rest of the nuts are pretty snug, you can break the LH and RH jam nuts at each end of the turnbuckle with just the 3/4″ wrench. You then adjust the turnbuckle with the 1/2″ wrench. Again, just a single 3/4″ wrench is needed to tighten the jam nuts when you’re finished.

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1984 96" with 8V92TA

(remodeled Liberty Coach)

Greenwood, MO

[Ken]

A couple of final notes:

1. Based upon photos I’ve seen, the alignment of and distance between the brackets probably varies from coach to coach. I also bought a tie rod end with female RH threads, but the clevis end worked best. I needed a single washer at that end for good spacing and alignment.

2. Everything I used has 1/2″-20 threads. There are 1/2″-13 options, but I decided not to mix and match. The turnbuckles I wanted to use are 1/2″-20.

3. Related to the threads – there was a problem with the fit of the male RH threads on the turnbuckle rod and the female RH threads on the coupler. When I did a test fit of the whole assembly, I didn’t notice that those two pieces were binding quite a bit. In the end, the threads of both pieces were really damaged. McMaster-Carr was great about sending free replacements, which was really appreciated given the $68 price of the turnbuckle rod. This just happened today, so I re-cut the threads of both pieces with a tap and die and was able to get things working. The threads are definitely compromised though, so I’ll switch to the replacement pieces when they arrive. I’ll do a test fit with some never-seize, and re-cut the threads if I run into the same problem.

[Archived]

Well Done!!

[Ken]

Chad, I would change out one of the mating parts so you don’t have stainless on Stainless. You will always be fighting Galling.