Tranny Fluid Gear Lube for a manual Tranny 75 Westy camper Bus

[75Westee]

I require information  please, regarding use of synth gear lube in manual tranny-axle on 75 Westy bus. 90W standard GL ?

Experiencing increasing down- shifting difficulty, and engaging into First gear (parked) usually must shift into 2nd gear  then into first gear (parked), sometimes helps if bus moves a little, slowly.

Tranny fluid 90W is much too thick (like Grease) in winter (Calgary) . Much better in summer BUT:

Require full clutch pedal travel to floor to disengage clutch disk, fully adjusted with new clutch cable last year.

I have heard do not use synth gear lube, it will ruin CV Jt seals and leak out everywhere, wear out syncro rings

others say it is OK to use, slight shifting problems, may be hard on synchro rings in tranny.

What conditions adjustments, etc should I correct, GL is likely 10- 15 years old in tranny, pls recommend type, brand, of replacement Fluid that will be much better than factory standard, but is compatible with CV Jts seals, improves shifting.

All comments, advice welcome

Regards

Paul

[Bruce]

, GL is likely 10- 15 years old in tranny,

Shame on you.    2-3 years under normal use is when you should change it.

If you go into your local auto parts store, you will find it is virtually all 80W-90 for regular oil, and 75W-90 for synthetic.  IMO, the biggest reason synthetic shifts better is due to the different viscosity more than anything else.

....shifting difficulty, and engaging into First gear (parked)....

Are you saying it is difficult to shift it into 1st gear while at a dead stop?  If so, you have other problems causing the clutch to drag.  It may be not enough freeplay at the pedal, or the bearing on the tip of the input shaft may be dry and dragging.

If your gearbox has never been rebuilt, it is already leaking, right? 
Synthetic won't ruin your CV joint seals. 
There isn't any gear oil that will hurt your synchros, that is a myth.  The oil companies tend to produce products to protect your parts, not attack.

I would recommend you try some regular gear oil in 75W-90.  It is hard to find this viscosity at the regular parts stores, however I have heard that Toyota specifies this.  Since it is difficult to find, Toyota sells it at their dealers. 

[75Westee]

Bruce , thank you for your fast informative response, much appreciated.

A biggg oops, ( many lashes with big wet noodle atop my noodle head) 2-3 years change interval,  I only use the Bus in the summer.  (poor excuse)
 I have in the past many years  (winter storage periods on axle stands), started engine, allowed to idle-warm
up for 20-30  minutes to heat up exhaust system, and circulate Tranny GL and engine oil.

IS this good or should I just not start engine until spring season.

....shifting difficulty, and...?Are you saying it is difficult to shift
it into 1st gear while at a dead stop?

Yes that is correct, until tranny fluid, engine have been driven and warmed up a little (not fully warmed)

I have approx 3/4 inch pedal freeplay, but was considering adjusting the pedal freeplay down to
1/2 inch freeplay to deter if clutch disengagement ie. shifting is improved.

Problem is the clutch pedal must be fully depressed against the floor in
order to disengage clutch /Shift into gear.

 Your opinion advice on this pls. 


" bearing on the tip of the input shaft may be dry and dragging"

My god if that is my problem I will have to remove the engine. A less than fun task. Will have to wait till fall when
I remove insurance on Bus and prepare /park bus for winter.

The gear box tranny has never been rebuilt since I owned purchased the bus in 1977.
Initially had a service shop service my Bus (1977 -79, too long ago to remember what was serviced, aside
from brakes, alignment, engine oil & filter.

 Have had Northlands VW in Calgary service the bus a few times, until they tried shafting me on some
non-service charges.

The tranny is not leaking anywhere, all accumulated mud gunk is light brown dry, not wet in appearance.

Bruce are you recommending synthetic over regular GL ?,  as you
state improved shifting, but you also recommend trying some regular gear
oil in 75W-90, available aat Toyota.

How much ie. quantity is reqd. for the tranny fluid.

Thanks Bruce
Regards
Paul

[Bruce]

I don't bother starting my sleeping cars in the winter.  I haven't seen any detriment in doing so.  You can continue starting yours in the winter if it makes you feel better.  Won't harm anything.

Since you said you do have difficulty shifting into 1st when cold at a dead stop, you do have a dragging  clutch or sticky input shaft bearing.  When stopped, the synchro isn't normally doing anything, so the temp of the gear oil should have no effect on shifting if the input shaft is stopped.  Address this issue, your synchro is taking a beating meanwhile.

I recommend you try some regular gear oil.  The stuff you can get from Toyota.  You're gonna have to look up the change quantity in your Bentley manual, I don't know it.