94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

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Targanon
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94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by Targanon » November 14th, 2013, 6:29 pm

Hi guys I know I have old B series 4x4 an all but its new to me.. and its the first 4x4 I have ever owned...

Ok I have a few things that are getting sorted...

but I have one that I am finding very strange....

Ok so I currently have 32 inch Maxxis 751's on my ute.. this is being fixed tomorrow with 31inch 771's going on instead.

but that not the issue with the speedo. when I first get in my ute and drive the speedo is about 8 to 10 k's out as in it reads fast....

but after about 2 hours of driving it comes good.. and read correct until you stop even just for traffic lights.. then its goes wacky again.. at city suburban speed's.

as I have not driven back out onto the hwy/ mwy or rural location after woulds I can't say if it goes back to reading correct...

I'm thinking that the sender unit is stuffed or clogged or something.. as I don't know the ute a don't know where to look for the sender unit..I would normally think near the rear of the Gearbox.. but as it has a transfer case attached would I still be looking in the same location and what does it look like... or is it something that needs to have the gearbox dropped to get to...

Thanks for any help you guys can give me.. please don't shock me. I got a good enough one today when I found out the tyres are FuckeD and need to be replaced.. ouch! I thought they would be dearer but I was not expecting that... and I had planned to get newer tyres..

Targanon
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Re: 94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by Targanon » November 17th, 2013, 7:16 am

OK so after having a good look around I found that it is infact a a cable or mechanical speedo..

So I guess the cable is on its way out or something..

If I pull the inner cable out from the underneath assuming I can pull it out from the that end.. would greasing it help and would I be able to get it back into the speedo at the top..

Peter Aawen
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Re: 94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by Peter Aawen » November 17th, 2013, 8:51 am

Sometimes (not all that often really) greasing the speedo cable can help, if it's got to that stage it's often better just to replace it; but while you are looking at that sort of thing, check out where the speedo cable goes into the transmission. It might even pay to undo that & carefully pull the end of the cable with the gear drive on it out of the transmission & inspect it. If the gear is worn, and they do tend to wear over time, it could mean you need to replace it - make sure that you get the right one for your diff gearing/tyre size, you can actually pick one that may make the speedo more accurate if you find out what's available and compare it to what your vehicle has in the diffs/the tyre sizes. Buuut, even before you get that far, if the trans end of the speedo cable is loose, or the 'O' ring is buggered, a simple solution for your problems may be just tightening it up &/or replacing the 'O' ring. Similarly, if the dash end of the speedo cable is loose, tightening it might solve your problems. And before you get too carried away with anything else, on many 4WD's with mechanical speedo's & speedo cables hanging under the vehicle, it is quite possible that the speedo cable has been caught on something and kinked at some stage - simply straightening the kink can often remove variations like you are experiencing.

So before you start pulling the speedo cable out and trying to grease it, check both ends of the cable to make sure it's OK; make sure the connections are good & that they also tight, not flopping in the breeze; check that the outer cable cover isn't kinked anywhere; and basically ensure that the simple physical/mechanical bits are all sorted before you start trying to resolve the harder & more difficult to achieve issues that might disappear if you sort the simple stuff first! ;)
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mydmax
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Re: 94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by mydmax » November 17th, 2013, 1:08 pm

Targanon
The reason the speedo goes reads fast and after while reads normal is the innermost pin bearing on the speedo needle shaft is DRY and the lube there has dried out and become gluggy.
After a stop it tends to grab and drag the needle around more than needed.
To fix it you need to use syringe and fine needle ( plenty of those around, pre loved) and use musicians trumpet valve oil or a drop of diesel fuel. It needs to be applied to both ends of the needle splindle so it runs free in both the body bearing and the inner bearing which is inside the aluminium drum at the base of the cable drive section.
The speedo has a bigger fat bush at the cable input and two fine bearing inside. Unfortunately the speedo has to be mostly disassembled to do it.

Targanon
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Joined: November 7th, 2013, 7:30 pm

Re: 94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by Targanon » November 17th, 2013, 6:52 pm

thanks for the replies guys most certainly something to do now...

think I'll go with the easy ones first like check for kinks and then maybe the lube job... LOL

Targanon
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Joined: November 7th, 2013, 7:30 pm

Re: 94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by Targanon » November 29th, 2013, 7:59 pm

Well I have the right diff in again.. so its got the right ratio now.. but as it stands the speedo is reading about 9klms fast... at 100ks and it still starts to read correctly after about 2 hours of driving...

so I guess I need to pull the dash out and dismantle the unit till I can put some trumpet oil or sim to the nidle..

Targanon
Here and there
Posts: 22
Joined: November 7th, 2013, 7:30 pm

Re: 94 Bravo 4x4 Speedo accuracy varies!? Any ideas why?

Unread post by Targanon » January 1st, 2014, 10:50 pm

OK So I still have pulled the dash apart LOL ... but I have noticed that the more I drive the ute the better the speedo is.

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