Oversized tires

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Does anyone know what is required to correct the speedo when going with different tires?

 

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Anyone know if this correts the speedo??
Have a look at this product:
(Take from the JRE webpage)
#ad


Abbott Electronic speedometer recalibration module

For those of you who want to change your tire size without affecting your transmission shift points and ABS; This will make the job quick and painless, easy 3 wire hook up, can be set for any tire size or gear ratio by flipping the appropriate dip switches using the supplied chart.

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• Eric D. Howard --- Baby BOMB'er! --- Member since April 8th, 2000
• 2001 Dodge Ram 2500 HD 4x4 SLT Auto Reg cab Cummins Turbo Diesel 4. 10 gear ratio LT265/75R/16 tires
• Patriot Blue Pearl Coat, Agate interior, Leather seats EVERY option - Coming next week Line-X Bedliner or Rhino
• In the VERY near future Power Edge Box, JRE 4" Exhaust, and Autometer Ultra-Lite Boost and Pyro Gauges
• transmission soon to have a new Torque Converter and Valvebody good for 400HP!?! Horsepower mods being discussed - I'll just say I am upgrading something electronically.

[This message has been edited by KatDiesel (edited 05-23-2000). ]

 

[Archive]

If your truck has 4 wheel ABS the Abbott ERA will keep tripping your ABS light. If your truck has only rear wheel ABS it will work fine. Basically it taps into the rear wheel speed sensor circuit which is also the rear wheel ABS sensor circuit. With 4 wheel ABS the Abbott ERA is correcting the rear wheel sensor signal while the two front wheel sensor signals remain uncorrected confusing the ABS computer, hence the ABS light keeps going off. This was my experience with my truck. The speedo was correct, but I'd rather have my ABS working. I ended up sending it back for a full refund. If you do order one, order from Rickson Truck Accessories. They sell them cheaper than Abbott does. Good luck -Glen




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1998 12 valve 2500 Quad Cab, A/T, 4. 10, Deep Amethyst, 4. 5" Skyjacker Double Flex lift kit, 36. 0"x14. 5"x16. 5" TSL Super Swamper radials on 16. 5"x9. 75" Weld Typhoons, Speedliner spray in liner, Raven high rise cap, J&J stainless steel Nerf-N-Steps

 

[Archive]

Originally posted by snowman:
Does anyone know what is required to correct the speedo when going with different tires?

For vehicles with speed pickup off the ABS ring on the rear axle, I think you can reprogram the CAB (Controller Antilock Brake) with a DRB. The two inputs are axle ratio and tire revolutions per mile. The reprogramming procedure is in the Chassis Diagnostic manual, not the service manual. I don't know who is willing or has the ability to reprogram; I haven't bothered. My 255/85s are 10% larger, which is easy to correct for in my head and doesn't seem to affect up the anti-lock performance.

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[Archive]

Originally posted by Craig DeYoung:
For vehicles with speed pickup off the ABS ring on the rear axle, I think you can reprogram the CAB (Controller Antilock Brake) with a DRB.

Last I knew, DC were having problems reprogramming the CAB for 'other' size tires, and the software has the 'other' option disabled.

I've got the Abbott box on my '98, and it does affect braking to a small degree (at about five to zero MPH, when stopping). Sometimes, the CAB keeps pulsing the brake for some seconds *after* I'm stopped.

I called Abbott and asked them why they are adjusting only *one* lead of the twisted pair. The response is that the design is good. My eldest brother, OTOH, who is an electronics engineer, says that *both* leads should be intercepted and modified to adjust the signal correctly, which is what I figured. I would really like to put a scope on the two leads at the CAB and see for myself just what the CAB is getting for a signal.

If you can deal with the RWAL brake system activating for a moment or two when you've almost stopped (remembering to give yourself a couple feet more stopping distance), then the Abbott box will work just fine. I set mine to correct the *odometer* to 1. 5% under; as the tires wear out, the odo will migrate to 1. 5% over-reporting. My speedometer has never been accurate; it's always indicated 4-8% high.

Fest3er