Howto: Replacing a Timbren Suspension Rubber Spring

[capnTelescope]

This post will only be of interest to a few, but I did it and wanted to share. I originally bought my Timbren axle-less suspension in the 3500# capacity, which was far too stiff for the actual loaded trailer weight of about 1800#. Things in the trailer were obviously getting bounced around, and that was on pavement. I got the HD version, which shares all the steel parts with the 2000# HD version. A call to Timbren confirmed that replacing the rubber spring would result in a smoother ride. A hunnert-some bucks later, two shiny new rubber springs arrived at the front door:

Top side left, bottom side right. The same part goes on either right or left side.

These are actually the old 3500# ones, which are perfectly fine. The new ones are softer rubber, but visually identical. PM me if you want the old ones. Free, but you pay shipping.

The actual replacement job is not difficult, but you will need some Manly Strength. Eat your Wheaties.

All photos were taken while doing the passenger side.

First, with the wheel on the ground, remove the bolt holding the rebound spring. That is the small donut shaped rubber part on the front end of the suspension:


Next, using a pry bar, WD40 and a little Manly Strength, remove the rebound spring and clean all mating surfaces:

Don't think you can skip removing the rebound spring unless you have Super Dooper Manly Strength (you don't). Removing the rebound spring is the shortcut.

Next, jack up the trailer BY THE FRAME until the wheel lifts off the ground. This will be higher than usual because the rebound spring isn't limiting downward suspension travel. You can't jack on any part of the suspension, as it needs to relax and open fully. I didn't take a picture, but you get the idea.

Remove the wheel.

Wrestle the old rubber spring out of the suspension. A good spraying of WD40 will make this easier.

Clean the surfaces that mate to the spring. Apply a thin film of grease to the top ...

... and bottom surfaces of the new spring:


This next step is the hardest part of the whole process. You're going to fit the new spring into the suspension. Specifically, you need to fit the top pin into the hole in the rubber, AND fit the forward rubber pin in to its hole in the lower suspension arm. If you can get these two done correctly, the rear rubber pin in the bottom will take care of itself.

You will almost certainly need some mechanical means to do this. May I suggest using a bar clamp, like so:

I also tried a rachet strap. Meh. YMMV.

So far, so good? Time to put 'er back together.

Remount the wheel, lower the jack, reinstall the rebound spring and bolt, properly torque your lug nuts, enjoy a and prepare to ride smoother.

Thanks for stopping by.

[kayakdlk]

Glad to see it worked out for you. I bought the Timbren 2000 lbs system (ASR2KHDS0) which is the 3500 lbs hardware and spindle with factory installed 2000lb springs and it has worked great. Your trailer should work much better now with the softer springs. I don't seem to get much if any bouncing, and things stay on my headboard during travel.

The advantage either way is you get heavier duty parts and it uses the bigger 3500 lbs hubs with 10" brakes which with a 1500 lb trailer makes for very little wear an tear on the axle and brakes.

Dan

[capnTelescope]

I bought the Timbren 2000 lbs system (ASR2KHDS0) which is the 3500 lbs hardware and spindle with factory installed 2000lb springs and it has worked great.

That's basically what I have now. I wonder if the rebound spring is softer on the 2000#. They didn't offer one, and I didn't ask. Mine started out as the ASR3500S6. I sure noticed a difference in stopping ability when I finally hooked up the brakes.

I've really like the Timbren setup. No worrying about exact trailer frame width, hub offsets or any of the other stuff that the torsion axles want to get you to the right size.

I haven't taken the trailer out on the road yet to try out the new springs. It can't be any worse. One time, my Dog Bowl Sink jumped clear out of its hole in the countertop.

Did you ever get the 2x2 cross piece welded on? That's my next step. My wheels look kinda like this: /----\

[kayakdlk]

Brad,

Did you ever get the 2x2 cross piece welded on?

Yes welding the cross member was one of the the last things I did before I took my trailer camping. Not sure I needed it but it hasn't hurt either. It is way up high so little impact to ground clearance like a regular axle.

I am not sure about the rebound spring if it different between the 3500lb and 2000 lb setup or the same. Might be worth a call to the factory to find out

Dan

[KCStudly]

If you think about it, the main "spring" sees the relative weight of the trailer/camper, while the rebound "spring" (pad/puck/cushion thing-a-ma-bob) sees the liveliness of the swing arms drooping out. Since the swing arm/hub/drum weight is essentially the same for a given axle rating, regardless of the trailer load and main spring rating, it kind of make sense if there is only one rebound pad part number available per axle rating.

If it ain't broke, don't fix it.

On the other hand wheel and tire choice could make a significant difference in unsprung weight, so maybe it is worth asking the question.

[capnTelescope]

Might be worth a call to the factory to find out

and

If it ain't broke, don't fix it.

I think I'll see how well what I have now works.

Since the rebound spring comes out/goes in snugly with the wheels on the ground, a softer rebound spring would only slow the rebound response, given that the unsprung weight is the same in either case. That may be a good thing when driving over a pothole, but I try hard not to do that anyway. I don't think I will be able to tell the difference either way. Okay, that settles it. I'll burn that bridge when I come to it.

Yes welding the cross member was one of the the last things I did before I took my trailer camping. Not sure I needed it but it hasn't hurt either. It is way up high so little impact to ground clearance like a regular axle.

Given my knock-kneed (or is it bow-legged?) geometry: /----\, that must be affecting tire wear. I already have the bar in there, it's just relying on friction now. It is up there, well out of the way. I have yet to come anywhere near needing more ground clearance. We'll re-evaluate that statement after the Land of Mordor Expedition.

[Specktre]

Hi Brad,
I have sort of the same problem then you but reverse. I have the acle less 2000hd but I think I am going to be overweight.

2100lbs total and need to add there is some stuff missing
1700 lbs on the axle
375lbs pn the tongue

I'll put more weight on the back to remove weight from the tongue or maybe some weight distribution system.

So I was wondering if you still have your 3500lbs rubber available?

I think I'm going to need some.
thanks

[Specktre]

Good day all,

I have a set of 2000lbs spring for Timbren Axle less. If you need some send me a private message and I will be happy to ship them.
You just have to pay the shipping.

I just have the rubber spring, not the whole suspension.

[Dave Nathanson]

Glad to see it worked out for you. I bought the Timbren 2000 lbs system (ASR2KHDS0) which is the 3500 lbs hardware and spindle with factory installed 2000lb springs and it has worked great.

Hi Guys, which spindle did you get? Straight, drop, or lift?
I'm planning to get the Timbren suspension; 3500# with the lighter springs. The TD has 30" tires, and I tow with a 4" lifted Jeep, so I'm guessing on the spindle.
AND I'd like to know if I can re-use my Dexter hubs & brakes from my current 3500# Dexter axle. Any input?

[capnTelescope]

Hi Guys, which spindle did you get? Straight, drop, or lift?

I got the 4" drop. With 15" wheels and a 2" drop at the TV hitch, the trailer runs level with my Tacoma with 4wd TRD package.

I'd like to know if I can re-use my Dexter hubs & brakes from my current 3500# Dexter axle. Any input?

IIRC, Timbren recommends the Dexter 10" drum brakes with this axle. It was a non-Timbren brake, and I'm pretty sure (without actually looking it up ) it was Dexter brakes I got. The brake mounting is pretty generic, so they should work.

[Specktre]

On mine I have straight spindle with 15" wheels. It give me around 16" ground clearance if I remember (I'll check tonigh). I have a 10' long trailer. Maybe I will go for a 4" lift later, I found the rear too low.