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Discussion Starter · #1 ·
I have a 91 rodeo, and the speedometer says im going about 15mph faster than i really am and wen i get to around 50mph (the speedometer is at 70mph) its at 3,000 rpms which is high to be steady holding it there!!! i changed the clutch and it didnt help... culd it be the rear end, or what??? ive also heard maybe the tranny but i dont know!!!
 

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what are the tire size?
 

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What size tires? I assume you checked your mph against another vehicle or maybe GPS? My 91 Trooper with 3.1 and 5 speed runs around 2500-2600 rpm at 55 if I remember correctly. I'd not be concerned holding mine at 3000 rpm though. Maybe I'll look at my rpm vs. speed a little closer next time out.
 

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Discussion Starter · #4 ·
sorry, i lost my log in info... i had 285 65 16 on it but went back to stock tires cuz i thought it was the problem but it wasnt... i also changed the clutch but the didnt help either... it wuldnt bother me except for i drive it every day and im at a steady 3000 rpms for like 30 minutes to and from work... the only other thing i can think is rear end or tranny but i dont know... i mite just trade for a trooper or a 4runner cuz i need a cruiser
 

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At 70 MPH my Trooper is over 3k rpm. Pretty normal actually. I have big tires but with the 4.77 gears it's pretty much the same as stock.
 

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On mine at 3000 RPM It is cruising right about 75. It has 235/15 tires and 4:56 gears. Auto trans
 

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Nothing wrong with your clutch, transmission or differential (rear end). You just have a speedo gear/final drive ratio/tire size mismatch. If you get the right size tires on it (bigger than you have now), your speedometer will read accurately.

I'm actually a little puzzled that the tires you had on it weren't right. They're what amounts to a 31" tire, which is about factory size for these things, or so I thought. What size tires to you have on it NOW?? That's something we need to know before someone can figure out what the problem is.

One last possibility: Did you buy it from someone who might've changed the gears in it for something lower (higher in numbers) to support oversize tires? Your speedometer is reading 40% low, which is a huge amount, considering it would take something like a 42" tire to "fix" the problem, if you still have the 285/65's on it and your speedo is still that far off. Someone please tell me my math is off, here...
 

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supersuzi421 said:
I have a 91 rodeo, and the speedometer says im going about 15mph faster than i really am and wen i get to around 50mph (the speedometer is at 70mph) its at 3,000 rpms which is high to be steady holding it there!!! i changed the clutch and it didnt help... culd it be the rear end, or what??? ive also heard maybe the tranny but i dont know!!!
How do you know it's off?
depending on gear ratio your 5spd could be running at 3000 rpm at 70 with smaller tires
 

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You need to find or borrow a GPS unit that has the ability to read MPH and check it that way. Most do. I mean I hate to bring it up but is it shifting into high gear if auto or if a stick are you getting it into 5th? I know dumb question but I had to ask.
 

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I've asked a highway patrol to check my speed a couple of times when I wasn't sure my speedo was telling the truth. The first time, the guy was cool with it and let me make about 4 runs past him at different speeds, calling my speed out on the CB on each pass. The last time he was a little pissy about it, but did it anyway when I asked if I should find another trooper and ask him instead, but in his defense, he'd been bitten by my dog a few months earlier during a "spot check" when he smiled (baring his teeth, which to any young dog is a show of aggression) and reached in the door to try and pet her.
 

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Rhodes said:
he'd been bitten by my dog a few months earlier during a "spot check" when he smiled (baring his teeth, which to any young dog is a show of aggression) and reached in the door to try and pet her.
:D Please :D don't :D show :D this :D post :D to :D your :D dog. :D
 
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