Hello all. My wife and I have had different campers off and on through out the years and decided to try an RV. We found a used one in our price range but need some guidance to be sure we are not buying something with a bad history. We found a 1991 Ford Cobra MTRH with a diesel motor . The odd thing is it has 3 wheels on each side of the rear axel. Two in tandem and the other behind the two. I have a haunch it is for the weight of it. I drove it on the highway on a slight windy day and noticed it swayed a little bit. I didn't know if it was because of the odd configuration of the rear wheels or if that is typical of all RV's Does anyone know the history of these? We don't want to buy it and then be disappointed. Thanks! Steve and Gail
Lucky Mike said
11:41 AM Mar 15, 2014
twin rear axles are for weight and smooth the ride out......the swaying cold have been low tire pressure.....faulty suspension.....loose steering...could be minor could be major. Look it over carefully, also have someone go thru the mechanics before purchase......the coach is 25 yrs old....if it had good maintenance you will have minimized problems......poor and just sat around , you will be doing some repairs
good luck on your find!!
kb0zke said
04:01 PM Mar 22, 2014
Welcome, Steve and Gail. Sorry I missed your original post - we've been pretty busy moving into our coach in preparation for our full-time adventures in two weeks.
Your wheel arrangement is something like this:
front of coach
0 0 steering axle
00 00 drive axle
0 0 tag axle
rear of coach
The tag axle is there to support some additional weight. I suspect that what you are looking at is a Class C motor home. That is a motorhome that is built on a van chassis, an E350 or E450 in your case. Many Class C rigs are pretty close to gross weight when empty, so manufacturers started adding the tag axle to help out a bit.
As Mike said, the sway could be due to any number of things. How much experience do you have driving large vehicles? If you are fairly low-time, you may be looking at normal behavior of a high profile vehicle in wind. You will soon learn to get used to that, and slow down when it is windy. On the other hand, if you are pretty experienced with high profile vehicles you may be looking at something with a problem.
If you haven't given up on the rig, you can do a few things to check it for yourself. One, make sure that all eight tires have the proper pressure in them. Unless you find some written information to the contrary, use the gross axle weight information and the Michelin pressure guide. That will get you somewhere in the ballpark. Two, see if you can SAFELY check the shock absorbers for leaks. The old bounce test doesn't work well on heavier vehicles, but if you can make it bounce that may be part of the problem. Third, see if you can weigh the rig. You want weights for each axle (steer, drive, and tag) at a minimum. If you can get individual wheel weights that is even better. Compare those weights you get to the gross axle weight rating. See if you can load the rig in such a way that each axle is loaded to about the same percent of capacity.
Hello all. My wife and I have had different campers off and on through out the years and decided to try an RV. We found a used one in our price range but need some guidance to be sure we are not buying something with a bad history. We found a 1991 Ford Cobra MTRH with a diesel motor . The odd thing is it has 3 wheels on each side of the rear axel. Two in tandem and the other behind the two. I have a haunch it is for the weight of it. I drove it on the highway on a slight windy day and noticed it swayed a little bit. I didn't know if it was because of the odd configuration of the rear wheels or if that is typical of all RV's Does anyone know the history of these? We don't want to buy it and then be disappointed. Thanks! Steve and Gail
good luck on your find!!
Your wheel arrangement is something like this:
front of coach
0 0 steering axle
00 00 drive axle
0 0 tag axle
rear of coach
The tag axle is there to support some additional weight. I suspect that what you are looking at is a Class C motor home. That is a motorhome that is built on a van chassis, an E350 or E450 in your case. Many Class C rigs are pretty close to gross weight when empty, so manufacturers started adding the tag axle to help out a bit.
As Mike said, the sway could be due to any number of things. How much experience do you have driving large vehicles? If you are fairly low-time, you may be looking at normal behavior of a high profile vehicle in wind. You will soon learn to get used to that, and slow down when it is windy. On the other hand, if you are pretty experienced with high profile vehicles you may be looking at something with a problem.
If you haven't given up on the rig, you can do a few things to check it for yourself. One, make sure that all eight tires have the proper pressure in them. Unless you find some written information to the contrary, use the gross axle weight information and the Michelin pressure guide. That will get you somewhere in the ballpark. Two, see if you can SAFELY check the shock absorbers for leaks. The old bounce test doesn't work well on heavier vehicles, but if you can make it bounce that may be part of the problem. Third, see if you can weigh the rig. You want weights for each axle (steer, drive, and tag) at a minimum. If you can get individual wheel weights that is even better. Compare those weights you get to the gross axle weight rating. See if you can load the rig in such a way that each axle is loaded to about the same percent of capacity.
Good luck.
Also make sure all 8 tires are under 5 years old. Here is how to tell - http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11 .