[man44a]

I ordered a 3.5 rear. It's newly installed but I didn't confirm what I was sent. I just assumed it would be correct. Any other ideas of why I am running such high RPMs. I really hate to take things apart to confirm.

 

[man44a]

Does the Formula figure in converter slippage.?

I don't think so. I do have the wrong converter for my combo, I know that, but I'm not sure what slippage feels like. How would I determine if slippage was part of the issue?

 

[man44a]

Thanks everyone. I'm going to work on confirming slippage, tire size, and also recheck my settings on the digital gauges. Will followup with findings.

 

[man44a]

Update:

Gauges are set correctly for 8 cylinders.
Tires are only measuring 26", so that's part of the discrepancy.

Here are my RPMs / Speed / RPMs with foot off accelerator
1450 / 30 / 1300
2000/41/1680
2200/46/1900
2400/51/2150
2600/56
2800/60
3000/64
3200/68
3400/72

So I'm guessing its a combination of tire size and converter slippage. Does that seem likely?

 

[man44a]

How are you measuring the tire? A 255/60/15 should be just over 27". Distance from the center of the hub to the top of the tire x2 should get you close.

That's how I measured. I even used a level on top of the tire. Right at 13".