[steak_knife]

losfer wrote:

i have seen that 12mm level bolt on many a gearbox , and i just went and checked my 88 model and it has it as well .

It has it as it is a retainer bolt for the extension housing, I`ve never seen it used as a oil level check plug. i have a Gv with 12mm bolt`s all over the box but thay arn`t check point`s. A lot of 12mm bolt`s on g/box`s hold internal shaft`s in place, with them removed the box WILL go BANG

[royce]

I'd post a page from teh FSM showing the level plug in the same spot but attachments arent working

[royce]

[losfer]

steknig wrote:

losfer wrote:

i have seen that 12mm level bolt on many a gearbox , and i just went and checked my 88 model and it has it as well .

It has it as it is a retainer bolt for the extension housing, I`ve never seen it used as a oil level check plug. i have a Gv with 12mm bolt`s all over the box but thay arn`t check point`s. A lot of 12mm bolt`s on g/box`s hold internal shaft`s in place, with them removed the box WILL go BANG

you still sure about that ?

[RobJ]

Alright,

Current situation having driven the car a bit more since topping it up is that 2nd works fine in all conditions, 1st however will go into gear happily at low speed but does not go into gear at high speed (50kmph for instance would be a problem)

Is it worth looking into this further?

[royce]

I would doubt anyone can get 1st at 50!!!!!!!!!!!!!! the syncros would be screaming

[RobJ]

Great, i couldn't remember what i could do with first before the change. Sounds like i've gotten out of this relatively unscathed.

Thanks for all the help, advise and for causing me unnecessary concern. There's nothing like hearing you'll have to take apart your gearbox only to find adding a little more oil fixes the problem

[paulv]

Next time you change it try a different brand and weight of oil...

[RobJ]

I didn't think there was much difference between brands???

As for weight, 80w was just what Castrol recommended for Sierras, might give 75w Valvoline a go next time though

[steak_knife]

losfer wrote:

steknig wrote:

losfer wrote:

i have seen that 12mm level bolt on many a gearbox , and i just went and checked my 88 model and it has it as well .

It has it as it is a retainer bolt for the extension housing, I`ve never seen it used as a oil level check plug. i have a Gv with 12mm bolt`s all over the box but thay arn`t check point`s. A lot of 12mm bolt`s on g/box`s hold internal shaft`s in place, with them removed the box WILL go BANG

you still sure about that ?

Yes, read it.... I have never seen the use of a 12mm bolt as a level check, before this thread, that sit`s below the fill plug,

[RobJ]

A bit of an update,
the gears are ok to use now but are still a little rougher than before.

I'm beginning to notice that there is some improvement after i've been driving a while and the oil has heated up.
What does this mean?

I assume it's a sign that a thinner oil (e.g. 75w) would further improve gear changes. Is this correct?