Front end alignment and pulling a 5er.

[TLightning]

quote:Originally posted by richfaa

"A lifted front end would cause the tires to dip. Wear bald on the outer edges in uneven spots" The rear of the truck only dropped 2 1/2 inches when the 3400 was attached but that was enough to take some weight off the front end.

I'm certainly no 5th wheel expert, but when my hitch was installed it was far enough forward of the rear axle to place some weight on the front end. I think it about 2" in front of the axle and amounted to around 400# on the front axle.

[richfaa]

So was mine Tom..Watched the shop do it with the template that comes with the hitch and this shop does dozens a year. Looking at my weight slip from the RVSEF weigh in at the Fall rally and there is 300 lbs on the front end with the 3400 attached.However there was nearly 1000lbs on the rear with the 3400 attached.

Had the airlift bags installed at Camping world in Kissmmee Florida. It is a very busy C.W that does a lot of RV work. Watched the tech do it and he had a hard time installing them properly.

[twindman]

So Rich,
Does this mean that your pin weight is only 1300 lb.???? Something doesn't add up???

[richfaa]

Maybe I do not know how to read the form.it says

Truck without trailer..front 5250 rear 4000

truck with trailer attached..front 5450 rear 6925
total axle load 12,375

Read the numbers wrong.

[richfaa]

' This is the original post from the OP......

"Two years ago I bought four Firestone Destination A/T tires. I drove those the first approx. 6 months before I purchased my 35' Montana fifth wheel. The tires have approximately 25K miles on them. Of that, probably 7k to 8K came while I was pulling my 5er. Two of my tires are so warn down (I mean no tread) that I had to replace them yesterday. I have been aware that I had an alignment problem for some time now, but waited before I took it in to get that corrected (my fault obviously).

Here is my question. The technician showed me on his printout how all four of my wheels were out of line. He also said that when you pull a heavy trailer you are more likely to have alignment issues and thus may need more front end alignments. Is that true???

We got way out in left field somehow,,,, He had two tires front I assume, worn bald??? and all FOUR of his wheels were out of alignment.How can that happen ????...In my post about my outside front tires being worn I stated that I had NO alignment problem.The front end alignment was PERFERCT and we determined that the issue was caused by the weight of the Montana on the rear lifted the front end just enough to wear the tires and make it APPEAR the alignment was bad..which it WAS NOT.

So how can a alignment problem cause all FOUR of the OP's wheels being out of alignment. My first thought was frame out of alignment???


"He also said that when you pull a heavy trailer you are more likely to have alignment issues and thus may need more front end alignments. Is that true???

He may have meant that if you pull a heavy trailer a lot you are more likely to have front tire wear. Don't know how pulling a hravy trailer alone can cause the front end alignmnet to go bad???

[Phil P]

Hello Rich

The rear axel can shift in the spring “U”` bolts, broken spring, broken spring center bolt or bent axel from an overload can cause an out of alignment condition. I have seen both conditions before but normally on a commercial vehicle that has been used with heavy loads like a dump truck.

The trailer axels can get out of alignment as well. Ours were out by ¼ in and they loosened the “U” bolts and were able to get them straight.

I have had my wife’s truck weighed with and without the trailer. I find that when I put the trailer on the front axel weight goes up to within about 100 lbs of the axel weight limit. The rear axel is still several hundred pounds light. I figure that if I loaded the trailer so I was at 23,400 lbs instead of 23,000 I would be at the front axel limit and very close on the rear axel.

This is typical of a fifth wheel type towing arraignment. The tractor-trailer tank trucks were the same way. When you reached 80,000 lbs all of the axels were near their weight limits.

I am about 100 miles from the Montana at this time and the weight slips are in it so I can’t give you exact weights.

Phil P

[richfaa]

'The rear axel can shift in the spring “U”` bolts, broken spring, broken spring center bolt or bent Axel from an overload can cause an out of alignment condition. I have seen both conditions before but normally on a commercial vehicle that has been used with heavy loads like a dump truck.'

You would think that a tire or alignment shop even a bad one would have seen that. When the rear axle on the 3400 shifted due to the bolts on the axle hanger coming loose we wore out those two tires in a few miles

[Phil P]

Hi

You never know what the tire wear will be. I took our trailer to a commercial truck trailer shop and put it on their frame machine because in 20,000 miles the G614 on the passenger side front axel was wearing like it had low tire pressure when in fact it has been over inflated going by Goodyear’s tire pressure chart.

It turned out that axel was ¼ inch further forward on that side and the Mor/ryde center hanger was bent out about 1 or 2 degrees. All the rest of the tires were OK.

I seriously recommend the installation of the X Factor from Mor/ryde I think both of my center supports have been bending in tight turns.

Phil P