Community Forums

gmcgene · 03-30-2017, 09:22 AM

1998 Alpine 36.
When turning at low speed I sometimes hear a noise coming from below the front seats. Turn left-it clunks. Immediately turn back to right- it clunks again.

Does not happen with every turn- but often. Like something is being stressed and relieved.

Coach drives fine- no looseness in steering.

Recently had a check ride at Henderson's Line Up in Grant's Pass, Ore. They discovered some other minor issues that were resolved. Did not find the source of the front end clunk.

Any Suggestions?

Unplanned Tourist · 03-30-2017, 09:39 AM

I have seen a similar situation in the spring hangers (shackles) having too much side play. Don't know if you have a solid front axel with springs or not. You will only hear the clunk at slow speed when turning.
Good luck.

wolfe10 · 03-30-2017, 11:46 AM

Check the sway bar bushings carefully.

Also, the bushings at the front of the trailing arms (the air bags are at the back of the trailing arms).

rskrbina · 03-30-2017, 01:47 PM

Quote:

Originally Posted by Unplanned

I have seen a similar situation in the spring hangers (shackles) having too much side play. Don't know if you have a solid front axel with springs or not. You will only hear the clunk at slow speed when turning.
Good luck.

X2. Worn spring hanger bushings.

Parkereng · 03-30-2017, 02:14 PM

Look to see if tie rod is touching the pushrod for the generator slide.

Old Scout · 03-30-2017, 04:22 PM

1998 Alpine--so no spring hangers; nor any push rod on genset slide [hydraulic]. By reputation, Henderson is pretty good and should have found any major issues. Agree with Brett--track bar bushings/brackets, and the front bushings on trailing-arm suspension are all good places to look [again, Henderson checked?????] Would also check mounting bolts on steering gear box frame, drag link end joints, and pre-load on wheel bearings. Maybe axle king pins too but less likely as a source of the noises.
PS--function of the metal torsion bands around the trailing arms has always been a mystery to me--but they always looked to me like a potential source for noise.

Unplanned Tourist · 03-30-2017, 09:16 PM

Get your coveralls on and a good strong light. Crawl all around under the front end and look for anything that's shiny indicating movement. Sometimes it's the strangest thing like a cross member or loose steering box mounting bolts. I've also seen broken brackets or cross member mounting areas moving.
Will it do anything if you are sitting still and have someone steer max right and max left a few times?
Hope you find it.

mbweitz · 03-31-2017, 11:37 AM

Ditto Brett Wolfe on sway bar bushings. Replaced ours 3 months ago to eliminate clunking in the front suspension. Bushings are on each end of two ~10" rods linking the sway bar to the frame. There is a set of 2 bushings on each end of the rods. Bushings not available separately - must be bought as a set with the rods @ ~$130 each, + special order shipping + tax = $290. Clunking gone.
Michael
2001 Alpine 36

gmcgene · 04-01-2017, 08:45 AM

mbweitz,

Where did you buy the sway bar and bushings? And how did you determine that was the source of your noise

I have suspected that was my problem but my bushings and clamps all "appear" tight and in good order.

Thanks to all for your replies.

Gene Barrow

Old Scout · 04-01-2017, 04:19 PM

...are we talking sway bar or track bar [aka hard pan], or both????

mbweitz · 04-01-2017, 11:08 PM

Gene
The probable source of the clunking noise was identified when I had our Alpine serviced at A&N Diesel in Redding CA, an excellent small diesel workshop. I couldn't stay longer there to have it fixed, so our Alpine Technical Mentor and friend picked up a pair of the "link assembly" rods & bushings at Franklin Truck Parts in Oxnard CA, and we installed them at his house. His air compressor tools were a big help.

Old Scout
It's the sway bar - that ~1.5" thick bar attached to the front axle side-to-side and that curves forward on each side. The short link assembly rods are attached to the forward ends of the sway bar, positioned vertically and attached at the top end to a bracket on the chassis frame. Two bushings on each end of the rods cushion the movement.
Michael
2001 Alpine 36

Old Scout · 04-02-2017, 07:38 AM

Yup-that's the sway bar. About 10 years ago, I was under the coach and noticed that WRV had put the metal washers inside the rubber bushings vs outside, so no real dampening on the vertical rods. Rubber bushings had totally deteriorated. Had some rubber bushings from a recent shock change on another vehicle--strikingly similar to the WRV bushings. Added additional metal washers to properly isolate the bushings. This "fix" has held for over 10 years and about 100k miles. Cheap solution--priceless satisfaction.
PS--similar bushings are readily available from NAPA...
PSS--while you are under the coach, check the bushings on the track bars, front and back.....