mackrmodel686st

R Model Upgraded Suspension

4 posts in this topic

I have a 1980 r model with mack axles and a camel hump suspension. I'm gonna be grafting the rear frame from a 1999 ch mack for the air ride suspension onto the r model. I also have the mack axles from a 1993 ch mack to go under the air ride. My question is, will the differentials from the 1980 mack axles work in the 1993 housings? The r model has a maxidyne engine with a maxitorque twin stick trans and don't want to change the axle ratios.

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I installed 76 diffs and hubs in a 96 CH 613 housings, it was a 40,000# airride with 38,000# housings. on my B61 I got the whole frame and slid it over the B frame all the way under the cab so it wont be a noticeable. on east coast R and F and B models the frames are the same with, the CH frame will slide over them. I just bolted mine ten plus years hadn't had any trouble.

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Check the ratios and see if they are the same or close with whats on the R than you are not messing around and swapping the axles (lots of work) or do like b61Mack said, strip the R rears and frame and slide the new CH frame and axles on and bolt her down. (that I think would be the easiest)

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I put a Hedrickson air ride with Eaton rears from a 2000 CH under my Superliner a few years ago. I stripped the Superliner frame down and slid the CH suspension and rears under it. Your R model frame is narrower than a Ch so you'll need to make up some flat plates and drill them to the bolt pattern of the CH crossmembers and suspension hangers and shim the game out accordingly. I'd check the ratio difference and see how close she they are before I would swap the rears. If the Ch ones are close I'd use them. But I'm not sure if the r model pigs will bolt up to the newer housings ??? Maybe.

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