Community Forums

smatth · 06-21-2014, 08:51 AM

I am a new member on this site but have browsed here before fishing for information. I feel the site is well done and informative. My reason for starting this thread is to hopefully find good advice on how to proceed with needed axle replacement. My TT weighs 6K lb dry and fully loaded I try to keep it just below 7K lb. It has two 3500 lb axles on leaf springs.

I had a bearing go bad on my last trip which damaged the spindle of the rear axle so axle replacement is required. My question is, since I consistently tow at near axle capacity, is it OK and safe to replace the 3500 lb axle now with an axle of a higher capacity, say 4500, and plan on doing the other at a later date? I have read, but not verified, that this can be done and still keep the same hub, tire and spring size.

Thanks for any thoughts and advice.
Steve

MSHappyCampers · 06-21-2014, 08:56 AM

Hi Steve! Welcome to IRV2! It's great to have you join the gang!

You will get better response to your question in another area of the forum. Maybe one of the Moderators will move it over for you.

Good luck, happy trails, and God bless!

**JohnRR** · 06-21-2014, 06:23 PM

Good luck with your search.

TeJay · 06-21-2014, 06:47 PM

Several points. First there may be a question if a 4,500 LB axle will fit. With the proper tools any axle can be made to fit. Issues would be if the heavier axle used larger tires, which I assume it would and that is also better as well, but maybe the area around the tire would be in question. Tires either rubbing on the frame or the wheel well area needs to be checked. We tried to have 4,000 LB axles installed on a TT that came with 3,000 LB axles and we were told they wouldn't fit. I don't believe they wanted to take the time to fit them.

Changing one axle now and the other later would compound the problems with different sized tires. If you want bigger axles that would also mean that you want tires that can handle the extra weight. that would mean going to a 15-16" rim and tire.

I have had experience with the straight axles and the Dexter Tor-Flex axles. They are much better than straight axles. Google the Tor-Flex axle and you will see what I mean. They are independent suspension. So you will eliminate the leaf springs, bushings and having to lube any wet-bolts. as well. The biggest advantage is when one tire hits a bump it won't transfer that movement to the other side of the TT like a straight axle will.

TeJay

Medico · 06-22-2014, 06:12 AM

Welcome and glad to meet you!

halfwright · 06-22-2014, 06:22 AM

My understanding of the difference is the thickness of the walls of the tube only. The brakes are different only is pad chemstry and magnet size.

TeJay · 06-22-2014, 07:58 AM

I don't know this for a fact but common sense tells me several things. When you increase from say 3,500 to 4,500 LB axles you need several things to become stronger to carry the heavier load. The axle tube will be larger in diameter or the metal wall will be thicker. The leaf springs will be designed heavier, more leafs, wider or thicker leafs. The tires have to be able to carry the heavier load. Fourteen inch tires, from my research when we had 3 TT's with 14" tires, would not support very much weight. They just don't make a great many choices in 14" tires to carry a lot of weight. So with a 4,500 LB axle you will have larger (15,16 or 17" rims and tires).

If you were to switch to the Dexter Tor-Flex axle they have no leaf springs. The axle is independent and uses a torsion bar, much like Chrysler used for years and years, and a rubber compound. I called Dexter and they tech told me the only difference between the 3,000 LB axle and the 3,500 LB axle was the amount of rubber injected into the axle housing.

If you stay with leaf springs that have 3,500 LB axles and increase to a 4,500 LB axle you will also need to increase the spring axle shackles and bushings. The 3,500 LB shackles and Nylon bushings will not stand up to 4,500 LB weights.

The last area of concern would be the TT frame. A frame designed to carry 7,000 LB's with beefed up axles to carry 9,000 LB's can not safely carry load anywhere close to that amount. I realize that all you are trying to accomplish exactly what I was trying or expecting to do with our 3 TT's. You simply want to SAFELY carry the load that the trailer was originally designed to carry and nothing more.

The above points and issues were exactly why we switched back to a MH from TT's. We tried for 4 years to have a TT that was safe to carry the load that it was designed to carry. It's unfortunate that many individuals find themselves in the same boat (or trailer) that you are in. You have a TT that is designed to carry a 7,000 LB load but you can't because the manufacturer has built your TT along with all the other TT's on the edge of destrucion. The axles, springs, shackles, bushings, tires, rims frame are all very marginal. There is vary little room for error. There are no shock absorbers to reduce TT sway. Most of the time TT tires don't come from the factory balanced. They do all they can to keep up the profit line.

I read in the owners manual that the manufacturer did not recommend carrying more than 1/4 of a tank full of fresh water. The tank is not designed to carry a full tank down the road. The straps and support design won't handle the weight safely. To me that's designed on the edge of destruction. When we brought our first TT home in 2010 the dealer had filled the fresh water tank to test the water system. I drove it home (120 miles) and the water tank was sagging down 7" and had a broken strap. That's one 120 mile trip with 1/2 full tank of fresh water.

We drove that TT to FL and back 2,000 miles. When we returned I rebuilt the springs, added wet-bolts and several of the shackle bushings were already completely worn through.

Need I say more????

TeJay