Hippie Posted August 9, 2003 Report Share Posted August 9, 2003 Finally brought the '88 GP I bought a few weeks ago home. It has the digital dash and the speedo is WAY off. It has the correct tires and the original trans but at what I believe to be 55MPH or so it only reads 40MPH. Could the speed sensor be wacked ? Thanks. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 10, 2003 Report Share Posted August 10, 2003 Could be the speed sensor. Could be the speedo itself. Have someone drive ahead of you at 55 and you drive 55 (at least on the speedo). See how far off it is. Quote Link to comment Share on other sites More sharing options...
Hippie Posted August 10, 2003 Author Report Share Posted August 10, 2003 Thanks for the input. Just found out that it is NOT the original trans. What would have been the standard ring and pinion in an '88 GP base model coupe with the 2.8 ? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted August 10, 2003 Report Share Posted August 10, 2003 More than likely, its the same trans you had before. Im assuming the original was an auto? and you have an auto now?? All the FDRs for the 4T60 (non-LQ1) are the same 3.33. See if you can find what kind of tranny was in there Robby Quote Link to comment Share on other sites More sharing options...
Hippie Posted August 10, 2003 Author Report Share Posted August 10, 2003 440T4/4T60 depending on who you ask, same trans just different numbers. But what it came out of I don't know, are there any codes stamped on the housing anywhere like the RWD cars that might tell me what ratio it has in it ? There was a 2.86 available for the 4T60/4T60E, that's what my LeSabre has in it, that combined with a speedo drive calibrated for something with taller tires could throw the speedo off quite a bit in the direction I'm seeing. Easily 10-15MPH. I believe some of the older 3.3 equipped cars may have used the 2.86 as it was not a high winder like the 60 Deg. motors. Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted August 10, 2003 Report Share Posted August 10, 2003 I really have no idea, but usually there is a tag somewhere on a replaced tranny if it was done by a dealer. If you did get a TH440-T4/4T60 from a non-W-body, that would explain your speedo issuses. You can always count the teeth on the ring/pinion gears and figure out your FDR, although that wouldnt be worth it? Only kidding. Anyway if the car drives fine and no other problems arise, then I guess you got a tranny from a non-W. Tell ya what, why not go test drive a stock W-body with a 2.8 in it, then drive your car. The stock one will obviously get off the line better cuz of the 3.33 FDR. Thats all I know of Robby Quote Link to comment Share on other sites More sharing options...
Hippie Posted August 10, 2003 Author Report Share Posted August 10, 2003 Previous owner did the swap, he owns a transmission shop and since it was for one of his kids and not a "paying" customer he wasn't too concerned about identifying what it came out of. I'm kind of hoping it is a 2.86 as eventually the car will get turned over to my youngest stepson when he gets his license and it doesn't need to be too quick. Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted August 11, 2003 Report Share Posted August 11, 2003 Can you get numbers off the tranny? If it came from an 89 or newer W-body, chances are, you only have to change your MEMCAL to one from an 89 2.8. Quote Link to comment Share on other sites More sharing options...
Hippie Posted August 12, 2003 Author Report Share Posted August 12, 2003 Can you get numbers off the tranny?If it came from an 89 or newer W-body, chances are, you only have to change your MEMCAL to one from an 89 2.8. I'll see what I can find tomorow, I have to go underneath for something else anyway. We're goint to try swapping reluctor's (sp?), my buddy has a large pile of 4T60 cores so I'm going to pull mine and then compare to some of his and try a different one, there are only 3 different ones for the 3 different R&P's available for the 440T4/4T60/4T60E. The tranny was already swapped when he got the car and he rebuilt the one that's in it never thinking it might have a different R&P than what came in it. Quote Link to comment Share on other sites More sharing options...
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