Speedometer, temp, and fuel gauge issues (fox t5/late 5.8 in classic)

SadbutTrue

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May 1, 2002
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I have a 66' with a 408 stroker (based on a 95 roller 351w block), with a T-5z. Posting to the fox forums because the engine / trans are more fox than classic (and the extra traffic doesn't hurt).

My stock gauge cluster has always had... issues. The temp gauge and pressure gauge in particular never worked well. So i got an aftermarket setup for those. New pressure gauge works well, no issues setting that up. But (Problem 1) - where is the best place to drop the temp probe? I have a Weiand Stealth intake.. and by my inspection the summit temp gauge is too big to fit where the stock sender goes.

Second (Problem 2), after I put my new engine / trans in, the speedometer started to fail. For a while, when power was applied, it would read correctly, but when power was let off the speedo would go to zero. This sounded to me like it losing engagement under thrust, so I tightened the old speedo cable at the transmission. Didn't make a difference, and eventually the problem got worse. For a while the speedometer would very briefly surge upward immediately after an upshift when gas was applied, but eventually it wouldn't even do that.

I've since replaced the speedo cable, without any change in speedometer behavior. I've checked the connection to the gauge cluster, and it seems fine. The speedo gear itself is old but looks fine... no obvious damage that I can see.

Did the gauge cluster fail? Is there something I'm missing? Its a new transmission (had it for 1.5 years but only has a 1-2k miles on it)... and the gear/old gable/gauge cluster worked fine on the 89' standard t-5 i had before.

Finally (Problem 3) - the fuel gauge has always hit 'E' with about 4-6 gallons left. Is there a way to 'reset' this? Its really not a big issue, but i did run out of gas one time a while ago, so if its just a matter of calibrating the sender that'd be cool.

Thanks all!
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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I'm going to move this to the classic tech forums because the issues you are having the classic members likely have dealt with more.
 

WORTH

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Nov 18, 2002
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1) Don't know what your manifold looks like, but the best place for the temp probe is in the intake near the Thermostat housing.
2) IF your speedo doesn't work, pull the cable off the speedo and see if you can turn the core , if you can the trans gear is stripped. If you can't, drive the car and watch the cable to make sure it turns, if it does, the speedo itself is junk.
3) If your fuel gauge is off you can pull the sender and bend the float rod to make it shorter, it may take a couple of tries to get it right.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
The temp sender probe issue can be resolved a couple ways, the best way I have found is to buy a thermostat housing from the early 70's that has a plug in the top.
there is a way to use adapters to fit into the intake but it takes some trail and error.