Broken trans mount.

[naitken]

I have a 2003 ultra classic trike with chain drive converted diff. I am running pretty stiff rear shocks (not air) and am having problems with
breaking the gearbox mount. The whole swing assembly has been replaced with new parts including bushes etc. Any suggestions on preventing this happening. The conversion has retained the side panier bags so have to watch suspension travel so diff doesn't hit underside of bags. Help.

 

[FLTR2008TRIKE]

This will limit the side movement of the transmission>>>
http://www.progressivesuspension.com/product/1484/touring-link

Have you checked the front engine mount and upper engine stabilzer for any issues?

 

[Lee H. Mann]

I have a 2003 ultra classic trike with chain drive converted diff. I am running pretty stiff rear shocks (not air) and am having problems with
breaking the gearbox mount. The whole swing assembly has been replaced with new parts including bushes etc. Any suggestions on preventing this happening. The conversion has retained the side panier bags so have to watch suspension travel so diff doesn't hit underside of bags. Help.

Are you breaking the rear transmission mount that the swingarm pin passes through ?
The twists that the swingarm tries to exert on the rear engine mounts and the transmission when cornering will cause a failure of the 2002 and later FLH-FLT model transmission mount with a straight axle.

In 2002 they changed the swingarm bearing (bushing) to a spherical ball and the transmission case rear boss was then made smaller for some reason. Some trike manufacturers found these failures quick and made a fix for them. They made an insert that went into the rear motor mounts (filled the void) stiffening them so that the mounts would limit the twisting of the swingarm, this eliminated that failure.

Below is a swinarm bushing fix that has the inserts.

http://www.vtwinmfg.com/webapp/wcs/..._10102_3314270_-1_141351_141398_141420_141424

 

[naitken]

This will limit the side movement of the transmission>>>
http://www.progressivesuspension.com/product/1484/touring-link

Have you checked the front engine mount and upper engine stabilzer for any issues?

Yes they were done at the same time as the other parts

 

[naitken]

Thanks for the link. Yes it is the rear trans mount. My wife rides this most of the time as I have the same model two wheeler.
She corners pretty hard, in fact I scrape my footrests keeping up. Will tell her to back off a bit and will try the new bushing.

Are you breaking the rear transmission mount that the swingarm pin passes through ?
The twists that the swingarm tries to exert on the rear engine mounts and the transmission when cornering will cause a failure of the 2002 and later FLH-FLT model transmission mount with a straight axle.

In 2002 they changed the swingarm bearing (bushing) to a spherical ball and the transmission case rear boss was then made smaller for some reason. Some trike manufacturers found these failures quick and made a fix for them. They made an insert that went into the rear motor mounts (filled the void) stiffening them so that the mounts would limit the twisting of the swingarm, this eliminated that failure.

Below is a swinarm bushing fix that has the inserts.

http://www.vtwinmfg.com/webapp/wcs/..._10102_3314270_-1_141351_141398_141420_141424

 

[naitken]

Broken Trans



Have finally got trans out and now can show break. When comparing the steel mounting kit I already have to the linked nylatron kit I can't seem to identify the advantage as they still use the rubber chasis mount. Can anyone help?. Very tempted to get existing housing welded up with additional gussets guys at work (I am an engineer) seem to feel the casting aluminium will weld quite well.. Has anyone tried this? :xzqxz::xzqxz:

 

[Lee H. Mann]

broken transmission mount

Both of the rear engine mounts are rubber with a hollow recess. The recess allows the back of the engine to move around and therefor the back of the transmission too. Filling these recesses (with the nylon bushings) will stiffen the rear mounts and reduce the amount of movement (twist) of the swingarm.

Once the swingarm is attached to the transmission the engine, transmission and rear axle become one unit. The weak link is at each connection and where they connect to the frame. Restricting the movement (twist) of the swingarm will save the stress on the rear if the transmission.

I wouldn't weld that piece myself !!!:AGGHH:

 

[FLTR2008TRIKE]

I have a 2008 with a 6 speed and have had this happen to me. See pics. Of my own doing I had forgot to check both sides of my swing arm locking nuts for tightness. Over time one of them backed off and the rear assembly was moving enough to break the casting of the transmission housing. I ended up replacing the transmission case and gear set

If your getting any kind of lateral movement its going to break the cast housing...



One thing I do now yearly is check my rear isolator bushings for any signs of separation of the molded rubber from the disks. If I see cracks I replace them both.

I also installed a Delrin front engine isolator from Sta-Bo

 

[Lee H. Mann]

See attachment epper: