R Model Cab Height

[Mr Black]

I am looking to restore a R700 or, if I can't find a R700, to convert a R600 to a R700. I have already asked a question about doing this on the forum but now have further queries about cab heights. One thing I have noticed about R Models in Australia (which is where I live) is that some have their cabs mounted very low and others are sitting up much higher (more like a Superliner). For this project I want the cab to sit up higher like a Superliner. I will be using a Western hood with the lowered guards so I think I could sit the cab and hood up to about 4 inches higher than standard without making the space between the tyres and the guards look too extreme. While I am looking for a suitable R600/700 I want to source the parts I need to raise the cab height.

So, with all that in mind, my questions are:

1. What is the best way to get the additional cab height?
2. Should I be sourcing Superliner cab mounts?
3. If I want air ride, is it still ok to use standard Superliner mounts for the front of the cab or do I need different front cab mounts for the air-ride also? I would think the air-ride only affects the rear cab mounts but I am new to Mack so I could be wrong.

Any help would be appreciated.

[Lmackattack]

For the rear cab mount You can use a superliner air ride cab set up. Use western or superliner front mounts. The front mounts were used with both solid and air ride cabs.

Not sure if you currently have a solid mount cab? But If you raise the cab up with a superliner cab air ride. You will also need to remove the x brace support that went between the radiator and firewall. Use rods angled from top of radiator to secure it down to the frame. This will hold the radiator still and let the cab move with the air ride cab.

This brings you to the next issue. The air ride cab will now need rollers on the fire wall where the hood rests. Rollers mount to the fire wall and locating guide plates to the hood. You may already have the guides on the hood....

Best advie is to look at a r model with an air cab and one without to see the difference..

[Mr Black]

For the rear cab mount You can use a superliner air ride cab set up. Use western or superliner front mounts. The front mounts were used with both solid and air ride cabs.

Not sure if you currently have a solid mount cab? But If you raise the cab up with a superliner cab air ride. You will also need to remove the x brace support that went between the radiator and firewall. Use rods angled from top of radiator to secure it down to the frame. This will hold the radiator still and let the cab move with the air ride cab.

This brings you to the next issue. The air ride cab will now need rollers on the fire wall where the hood rests. Rollers mount to the fire wall and locating guide plates to the hood. You may already have the guides on the hood....

Best advie is to look at a r model with an air cab and one without to see the difference..

Thanks for this - it has been very helpful. I am starting to understand how these R models are set up. Out of interest, does your RS have air-ride? If so, does it make a significant difference? We mainly use cabovers in the region that I am in due to length restrictions. You would shatter your spine in a cabover that didn't have good cab suspension. I am curious whether it is as noticeable in a 700 series R model given the driver sits so far from the axles. Thanks again

[Lmackattack]

My RS700 was factory solid mount cab. 2 years ago I bought a used superliner air ride cab set up and installed it my self. It bolted right up to the cab but I had to fab up some of the mounting brackets to the frame. It made a big difference limiting road shock and bucking. It has camelback rears so it's no caddy but the air cab made a nice improvement in the ride quality.

[fifth wheel]

The RS/RL cab is a few inches higher than the R, and the RW is higher than the RS/RL, with the western hood I would keep it stock height.

FW

[Lmackattack]

I measured my stock RS cab bottom to upper frame rail flange and it was a difference of 1-2" compared to that of a superliner.

If I recall the RS cab sits about 4-6" higher than an standard R model

[Mr Black]

The RS/RL cab is a few inches higher than the R, and the RW is higher than the RS/RL, with the western hood I would keep it stock height.

FW

Thanks FW - I guess that means there are different cab mounts for a RS/RL as compared to a standard R. I have no chance of finding these in Australia. Could probably get some shipped from Manders.

[Mr Black]

I measured my stock RS cab bottom to upper frame rail flange and it was a difference of 1-2" compared to that of a superliner.

If I recall the RS cab sits about 4-6" higher than an standard R model

I appreciate your help with this. I might send an email to Manders to see if they have any RS/RL mounts. They might be able to tell me exactly how much higher a Superliner mount is compared to a RS/RL mount. Will ask about second hand air-ride also. Thanks

[Whiskymack]

http://www.bigmacktrucks.com/index.php?/topic/7279-air-ride-cab-modifaction-r-model/

I don't know if this link is of any use to you. It's more about air ride but might be interesting.

I think you also need to bear in mind that the Australian spec Superliner was a different beast to the US one. The Australian truck had the same basic frame as the R model whereas the US Superliners had a totally different frame. The same applies to the US RS/RL series which had a different frame to the Eastern built and Australian R series. You might find that cab mounts from an Australian Superliner or V8 valueliner would be the best match for your frame but I'm no expert and could be wrong.

There is a website called hcvc.com.au where some people seem to have done similar things. I think that if you search the gallery pictures on this forum there is someone in your country who built an R700 Rubber Duck lookalike out of a Flintstone R600.

Hope this helps.

[Mr Black]

http://www.bigmacktrucks.com/index.php?/topic/7279-air-ride-cab-modifaction-r-model/

I don't know if this link is of any use to you. It's more about air ride but might be interesting.

I think you also need to bear in mind that the Australian spec Superliner was a different beast to the US one. The Australian truck had the same basic frame as the R model whereas the US Superliners had a totally different frame. The same applies to the US RS/RL series which had a different frame to the Eastern built and Australian R series. You might find that cab mounts from an Australian Superliner or V8 valueliner would be the best match for your frame but I'm no expert and could be wrong.

There is a website called hcvc.com.au where some people seem to have done similar things. I think that if you search the gallery pictures on this forum there is someone in your country who built an R700 Rubber Duck lookalike out of a Flintstone R600.

Hope this helps.

Hey, thanks for this - really good points. I didn't know the USA Superliner had a different frame but have noticed it has a different cowl to standard R models. In Australia, the Superliner is really just a R700 with a different hood (at least that is the case with the early ones). The more I think about it, the mounts from an Australian Superliner might be the best. The V8 Valueliner might be a good source also given the cab was raised for the sloped hood. Will see what I can find from local dismantlers. Cheers