B model air ride conversion questions.

[b61fred]

Hi, 

  I have been wanting to add air ride to my b61 for a number of years now. I have an Air Liner air ride with some mysterious rear axles in it. My tractor has tandem rears with Mack 5:13 gears and the mystery axle is a 3:73. The 237 would do fine ratio wise but I was wondering can you use the rear axle of the tandem and make a single drive instead of a tandem? If I was to get pictures could anyone identify it? 
thanks

Fred

[Mark T]

Pictures are always good.   I'm sure someone could make a suggestion.

[davehummell]

That 3.73 will give you a better speed on the interstate if you decide to run it. I put a single axle off a freightliner on my B and with my 13 speed double over trans it rolls right along down the highway. With the gearing that was in it I came back from the show at the Mack museum and 50 up 81 was not ideal back in the 70's it was but not now.

[b61fred]

I agree on the gearing, don’t see much over 40,000 lb GCVW with truck, trailer and a few farm tractors so a 6 wheel truck would do the job just fine. I’m going to get a picture of the axle tonight to get a ID on the unit. I just want to use the rear axle of the tandem set.I would love to get a inter axle locker for it though.

Edited June 4, 2023 by b61fred

[doubleclutchinweasel]

I have seen rear tandem axle used as a single.  Main thing is getting all the mounting brackets right.  For instance, using a rear drive axle off a camelback spring will need different brackets to attach to a single axle arch spring.

[Vladislav]

An axle off a tandem bogie can be used as a single drive if attached properly. At least I see no reason it couldn't transfer the torque. It shouldn't have an interaxle diff for sure so preferrably a RR axle.

Another reasonable single drive option on my mind is a half of Neway setup. You just take one axle with Neway brackets and equalizers etc and mount it to your chassis. Not a correctly looking design for a B-model. But correctly looking for a classic Mack truck in general.

There's one more interesting point in that story. Usually axle housings used with Neway have brackets (ears) welded to the housing at the bottom side. So those are not axles which ride on Camelback. But one set of Neway's I could locate locally had axles of the style used with Camelback. There were adapting brackets (actually thick plates with ears welded onto) which were bolted right to where elephant pads use to be. So Camelback style axles were mounted to Neway equalizers and all seemed as factory parts.

[Mark T]

55 minutes ago, Vladislav said:

An axle off a tandem bogie can be used as a single drive if attached properly. At least I see no reason it couldn't transfer the torque. It shouldn't have an interaxle diff for sure so preferrably a RR axle.

Another reasonable single drive option on my mind is a half of Neway setup. You just take one axle with Neway brackets and equalizers etc and mount it to your chassis. Not a correctly looking design for a B-model. But correctly looking for a classic Mack truck in general.

There's one more interesting point in that story. Usually axle housings used with Neway have brackets (ears) welded to the housing at the bottom side. So those are not axles which ride on Camelback. But one set of Neway's I could locate locally had axles of the style used with Camelback. There were adapting brackets (actually thick plates with ears welded onto) which were bolted right to where elephant pads use to be. So Camelback style axles were mounted to Neway equalizers and all seemed as factory parts.

I  might be wrong, but I think the adaptor  you're describing for the Nuway is the same as the one for a Hendrickson.  He's talking about using an Airliner. That seems like an easy one to use as a single axle. See them all the time. Might be a challenge to get the drive line down to the level of the pinion though as compared to Mack top load double reductions.  Fairly large drop compared to wheel base.

[Mean Green]

The new ratio will make a world of difference on the highway I did a tandem air ride cut off on my original single axle it rides better and is way faster you don’t feel like your pushing it down the road now and I don’t see why you couldn’t use the entire rear axle with suspension  on your frame when I did my swap the frame slid right over my b frame and I dust bolted it together but the new frame was taller than the original

[doubleclutchinweasel]

Yeah, seems like Mack frames were slightly narrower than most. 

[Mark T]

Half inch... isn't it ?

[Mean Green]

That sound about right made it easy to install the cut off

[b61fred]

Went out a got some pictures of the axle I want to use. I think it’s a sq100 axle. I think the rear unit will work well, it even has the same series driveline as the b model. I think I can use 1/4 inch fish plate on the sides of the frame to take up the difference on the frame width. The airliner suspension on the tandem is in theory two independent units working in parallel. Here are some pictures…

Edited June 6, 2023 by b61fred
Pictures

[Mean Green]

That sounds like a good plan good thing you say the drive line is the same I know I had problems with mine it was miss matched both size and style I ended up getting a yoke to fit the rears and welded it to my driveshaft so now the drive shaft has a smaller press in caps on the front and larger strap style u joint in the rear

[davehummell]

First thing is really look over those old air bags just like tires they have life limit. when I slid in the rear I went up to Cooks and bought two new ones one less crappy thing to worry about mine had slow leaks.

[b61fred]

I would change all the rubber items for sure, they only last so long. Brakes and shocks as well. Is this a SQ100? My drive line angles would work because I’m going to install it closer to the rear of the truck for more wheel base. My truck doesn’t have front brakes so I’m going to have to add those too. 

[Mark T]

They look to be old Rockwells.   Maybe even from the Timken era ???  Not sure what model.   Still seems like it should work, especially if you freshen it all up like you said.