Re: Manual transmission roughness



On 12/6/2010 6:35 AM, Scribe wrote:

"GM homepc" <wiebe008@xxxxxxxxx> wrote in message news:idhddp$4hh$1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On 12/5/2010 1:14 AM, Ray O wrote:
"Scribe"<Scribenospam@xxxxxxxxxx> wrote in message
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A Toyota Avensis 1.8 GS, manual gearbox. It has done 113,000 miles. A
slight vibration has occurred in the gearbox. It is usually when
decelerating and is reduced when dropping to a lower gear. It is not there
when accelerating. When depressing the clutch and keeping engine at the
same revs it go away, which indicates it is not the driveshaft. Does
anyone know what it is? Clutch?

On another point the likes of Slick 50 say there products prevent noises
in old gearboxes and rduce wear. Are these additives and good? Do they
work?


First, make sure that you have the correct transmission fluid - most newer
Toyotas use ATF in manual gearboxes and using gear oil will cause difficult
shifting.

Check your transmission mounts and engine mounts, particularly the ones
nearest the firewall as broken or worn mounts can cause the symptom you are
describing. I can't think of anything internal in the transmission that
would likely cause a vibration only on deceleration.

Stay away from additives as most cause more harm than good. Additives can
change the way the synchros bite the cones, causing rough shifting,
particularly downshifting.
I was thinking of using

Synthetic Manual Transmission and Transaxle
Gear Lube 75W-90 API GL-4 (MTG)

http://www.amsoil.com/storefront/mtg.aspx

on my first manual transmission fluid change just due on my 07 Corolla. I called the dealership and they said that synthetic oil is rarely used in manual transmissions. They didn't discourage the idea, but they didn't feel is was really necessary. I wanted to get easier shifting in the cold weather.

That is what I want. Dealership advise? Mmmmmmm. They tend to just quote out of the manuals in my experience.

Any advise?

After a lot of hunting, I finally found a transmission shop in town who sells this Amsoil product and keeps it in stock regularly. Paid $15.10 plus taxes per quart. I expect to have it installed in the new year when my ECM recall gets done. I'll try to post the results in a few months time.
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