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50mph + noises


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Gents

Been having a few transmission problems in general.

Have got rid of a knocking sound when taking up drive - worn rear propshaft splines.

Still have a knock when drive takes up, am planning to replace the ball joint and there is probably slack in the diff.

More importantly when above around 50mph, with acclerator down, i get a transmission type whine. This fades when i take my foot off the accerlator, and seems to disappear if i disengage the clutch.

So firstly any thoughts on likey candiates? - i assume gearbox and transferbox.

The noise appears in either 4 or 5th and gets considerably worse with speed. - does this suggest transfer box?

I currenty have a bit of an oil leak around this rear prop output flange - does this give any indication?

Would really appreciate any thoughts on tests etc to further identify the culprit.

Also have a planned camping trip of next week end round trip of around 500mph - if its the transfer box can i risk it?

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might be transfer box or main gearbox bearings, but as it goes away with the clutch disengaged, it could be the release bearing.

are the fluid levels correct & the correct grade ?

are the wheel bearings OK & the hub driving member splines.

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If it was me I would check all the obvious things (like Western says) then check the fluid levels of the g/box and transmission and if all was OK I'd go camping (@ 500mph...sounds like fun). I would keep an ear out for any changes in the whine that occurs as time progresses but it would be hard to diagnose what it is until you have a few other pointers.

MY lt77 box was driven with low oil in it for a while and the noise was horrendous but she kept going. I have her stripped down now and it's quite mess but repairable. A slight whine is something to keep an eye on but not the end of the world (or your transmission).

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A knock when taking up drive could wear on the gearbox mainshaft. This too could maybe explain the whine depending on exactly what that whine sounds like. The best way of ascertaining the degree of wear is to chock the two front wheels, handbrake off, mainbox in first and jack up a rear wheel. Remove the PTO cover to the left of the handbrake and you will be able to see the gearbox mainshaft in the centre and the transfer case input gear around it. By rocking the handbrake drum you will be able to rock the gear around the shaft thus getting some idea of wear / backlash between the two.

When these finally give up you loose all drive.

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cheers guys i shall check the drive flanges and half shafts today and report back. Do i just remove the wheel and look for relative movement?

Oil being changed just in case too. Are there any other tests i can do too see if it is the release bearing?

In terms of the transfer box / gearbox are there any checks i can do?

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To check the mainshaft splines: Remove the PTO cover (6 bolts on the back of the transfer box, directly behind the main gearbox) and pull the input gear (it should just slide right out on a 1.41 box) then examine the splines that are exposed on the shaft.

They should be nice and square with no obvious chafing/wear marks.

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right

have done the check on the main gearbox there appears to be very limited slack between the shaft and gear.

however when it came apart there was a lot of "glunky" oil with some debris. - i didn't really expect this - i have uploaded some photos (see next repy too). In additon in the centre of the shaft it is very dry with a dry carbon like debris.

Do you have any thoughts on this.

I have the 1.41 ratio box - can i just get hold of the gear and pull it out - what sort of force is normal?

post-2882-1241451312_thumb.jpg

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Gents

apologies for the continued questions

I've removed the cover at adjacent to the handbrake drum, which shows the gearbox output shaft and transfer box input gear, as suggested in previous threads.

There is around 15deg of slack between the transfer box gear and shaft when you rotate a prop - is this excessive? or would this be the cause of the previously mentioed whirrling above 50mph.

I changed the gearbox, transfer box and engine oil - nothing odd to report. However still get the whirrling noise? However do have an oil leak on the front proposhaft outlet flange.

Whats the consensus do i have an immediate problem - or can i risk a 300 mile drive?

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to be honest - i was a bit pushed for time. - and couldn't do anything to solve it so decided on leaving it for another day.

i was planning to order a new input gear - however a you suggest it could equally be the spines on the shaft - if this is the case - is there a replacement part that can be fitted and how would you go about doing it?

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Guest noggy

hell, mine makes weird noises all the time past 50mph, i just wear ear defenders.....

(my kenlowe fan makes a weird noise when i get past 50 aswell when the wind is actually spinning the fan faster than its own motor can)

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Jim - Pull the input gear out and clean it up, you should then be able to examine the spines inside it to see if they are worn, if they are mashed on one side you know it hasn't got many thousands of miles before you loose drive...

with the input gear out of the way you should be able to examine the gearbox output shaft splines...

If you do buy a new input gear make sure you get a cross-drilled one (allows better lubrication of the splines) rather than a straight swap.

I don't think the input gear would be responsible for your whiring noise, but could be wrong..

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