FG 637 crew cab tearing front cab mounts

[offroadpup]

Hi all,

I was wondering if anyone had experienced problems with crew cabs tearing the front cab mounts when offroading in rough terrain.

Our new camper body is a 4 point mount with twin pivot system and totally decouples the body from chassis twist allowing the chassis to flex and conform to the terrain fully, but this leaves the cab as the only part that is very rigid and quite long and mounted to the chassis in a way that wont allow twist over its length, and it seems that during our recent offroad shakedown I've torn the rubber right around in both front mounts. I had new rear cab mounts installed just before the trip.

The truck is a 2000 model and has done almost no work since 2003 until now (only has 77,000kms on it) so I'm trying to determine whether it will just happen again if I replace them or whether they were just old and hard.

I'm also wondering whether its a common problem, or whether its because the rear mounts are supposed to be left loose (they are pulled down hard now whereas the old ones were loose and banging on bumps), or indeed whether I need to build a spring mounted system for the rear ones to allow the chassis under the cab to twist a bit more freely.

Any feedback on it would be welcome.

Cheers -Andy

 

[whatcharterboat]

Hi Andy,

What were the original cab mounts like before you replaced them??

I have not heard much about problems with the front mounts on dual or single cabs or single cabs for that matter.....

but I have seen the sheet metal bracing for the rear mounts crack away from the rear of the body and always thought that if I owned a crewcab that I'd look at spring mounting the rear cab to allow more movement than the 4 x OEM rubber mounts.....that area around the chassis below your rear seats is where you will normally get trouble if it's going to happeN whether it be the front mount of a camper, service body, rear mount of the crewcab or whatever .... also I have never been a fan of pivot mounted bodies on the FG's (see the seperate thread) and maybe this has effected the chassis movement somehow......really I am guessing without even seeing the thing but I don't believe spring mounting the cab would hurt and may help take stress off the front cab mounts.

There's nothing stupid going on with the bullbar mounting or any other bar work that could be effect the the front cab is there? Or excessive weight being carried in or on top of the cab?

Regards
John

 

[offroadpup]

Hi Andy, What were the original cab mounts like before you replaced them??

Hi John and thanks for the help. I've only replaced the rear ones only, they were replaced at service so I did not sight them but the bolts through them were floating about an inch on the right side and both knocking so I'd say they were pretty warn.

I'm also not sure how they look in normal condition either, I did not pay much attention to them when looking over it before it happened. Here's how the left front looks now;

There's nothing stupid going on with the bullbar mounting or any other bar work that could be effect the the front cab is there?

No strange barwork, only a pretty bog standard bullbar mounted in what looks like a pretty neutral way to me;

Or excessive weight being carried in or on top of the cab?

Nothing other than people and light jacking equip under the back seat. We did have a full compliment (7) on-board at the time, and it did begin very early in the test as we were leaving the camping area for the trails so you might be on to something. We had 3 good sized adults in the front (I'm not talking the 3 sumos off the 'not so squeezy' ad though) , one adult and 3 kids in the rear. Front left was the first noticeable noise where two of the adults were located.

There was one possible compounding factor I neglected to mention earlier too, the chassis is something like 850mm longer than standard (4.1m wheelbase). I guess that would have some effect on chassis movement, not really sure how significant though.

I've not had the mounts out yet, its still drivable so was going to get some in hand before doing the work so I can keep it mobile to do stuff on. I suppose its not impossible that they were partially torn previously but the tears look pretty fresh and black (see photo above)

Any idea what the in-cab carrying capacity should be roughly ? I'd have thought at least 3 solid workmen in the front would be the aim, also false advertising if it cant take 3 Sumos!

Thanks again for your help John.

 

[Ford Prefect]

All I can say is I want to see photos of this truck!!! haha

Sounds like a really nice vehicle, and I am sorry for your loss.

Any way you can get a hand on them and see if they feel like they have a bit of dry rot? Sitting around for ten years will cause the rubber to dry out pretty badly in certain conditions. Grab a chunk of that rubber and tug on it really good. If it breaks off with ease, well, you have your answer. If it is pliable and stretches a touch then you may have a bigger problem. Either way you should have a lot more info than you do now.

I know that may seem a touch obvious, and perhaps you have done it already, but I am just spit-balling here.

 

[whatcharterboat]

Hi Andy,

Sorry...I thought you replaced the front mounts before your trip.....I mis-read that.

I don't think they have any rating specific to the load in the cab other than the obvious axle load rating. I reckon just replace the torn mounts , keep an eye on it and if it happens again in then worry about it. Maybe Brian is right and they have gone hard for some reason with age.

Regards John.

 

[offroadpup]

All I can say is I want to see photos of this truck!!! haha
Sounds like a really nice vehicle, and I am sorry for your loss.

Yeah I'll have to get some pics together and post them up. There's one on the "Canter Rims" thread. Lack of time is always the problem. I did take a heap of photos during the build with the intention of blogging it, but most were lost when my phone was stolen.

Any way you can get a hand on them and see if they feel like they have a bit of dry rot? Sitting around for ten years will cause the rubber to dry out pretty badly in certain conditions. Grab a chunk of that rubber and tug on it really good. If it breaks off with ease, well, you have your answer. If it is pliable and stretches a touch then you may have a bigger problem. Either way you should have a lot more info than you do now. I know that may seem a touch obvious, and perhaps you have done it already, but I am just spit-balling here.

It should have been obvious, but wasn't to me :s I had planned to check them out fully once out of the truck but just thought I'd ask if it was common first. I've had a pick at them and yeah I'd class them as crumbly and suspect, pinching a bit off with a pair of pointy nosed pliers was too easy, and worse the bits I pinched off broke into a few pieces each. I'll go ahead and get some new mounts and see how it goes.

Thanks for your help and for your help too John.

-Andy