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Clonking from trans/axle

Posted: Mon Sep 28, 09 8:50 am
by Anonymous
Finally got the motorhome running again ( guess we'll put it down to irratic fuel gauge :oops: ). Took it out for a little run at the weekend and had a listen to the "little" clonk that I was told by the seller was there.

Its definetly there, quite a loud clonk. With the choke on and the engine revs up its there when you put it in drive or reverse, but when the chokes off and its at warm idle speeds it only does it in reverse ( funnily enough so does the Belvedere), I have topped up the trans fluid as it was a little low and will check rear axle oil level and prop UJ's. Just wondered if I was looking in the right direction or should I be checking something else??

Posted: Mon Sep 28, 09 9:40 am
by latil
Possible worn bush in trans output housing,where the prop slides.Mine clonked there.Check the usual UJ's and the diff input shaft,loose prop yoke or worn pinion/ring gear. Worn halfshaft splines. trans rear mount,rotten rubber.

Posted: Mon Sep 28, 09 10:10 am
by Blue
Check the UJ,s for wear if none is present then it is play being taken up in the diff. If the diff is otherwise quiet, I wouldn't worry too much about it. Check the tickover speed with the engine warmed up, and if possible slow it down a bit, if it is possible to slow the speed when it is on choke do that as well. A slower tickover speed will allow the torque convertor to absorb some of the shock as you drop it into gear.

Posted: Mon Sep 28, 09 10:17 am
by Anonymous
Thanks guys, I'll check it out one evening this week.

Posted: Mon Sep 28, 09 12:16 pm
by MilesnMiles
I've had the same experience especially from cold. I tend to start the car in Neutral to get the trans pump working on the convertor and slip the car into D, then back thru into R to back out of the drive. As long as there isnt excesive revs the bang reducesquite a lot.
The same is also true of my Merc and apparrently Buick Grand Nationals :?