Gear Ratio dosent match up

[Dean2]

no it dosent. tries 4 different calcs.

At what point do you just decide it is what it is and you don't have the ability to figure it out, even with a lot of help? You manually tested the gear ratio and got 3.55 and it is supposed to be 3.21. So is it really a 3.55 or did you measure and calculate wrong? Have you looked up the transmission gear ratios for your specific year and model of pickup. Do you know for sure none of that was changed, same with the front and rear gear ratios, because if the rear is a 3.55 and front is 3.21 you have a major problem.

Even when you put numbers in the calculator you get a different result than the rest of us? At some point, us trying to help remotely just doesn't work because nothing we do agrees with your numbers or measurements. Best of luck. Let us know if your ever figure it out.

 

[Wild one]

At what point do you just decide it is what it is and you don't have the ability to figure it out, even with a lot of help? You manually tested the gear ratio and got 3.55 and it is supposed to be 3.21. So is it really a 3.55 or did you measure and calculate wrong? Have you looked up the gear ratios for your specific year and model of pickup. Do you know for sure none of that was changed, same with the front and rear gear ratios, because if the rear is a 3.55 and front is 3.21 you have a major problem.

Even when you put numbers in the calculator you get a different result than the rest of us? At some point, us trying to help remotely just doesn't work because nothing we do agrees with your numbers or measurements. Best of luck. Let us know if your ever figure it out.

I'm guessing he hasn't got the right transmission gear entered into the calculator,he's either mistakingly reading his dash wrong,or he's not counting the shifts right.Either way he wants to figure it out,he's definitely in the 1:1 transmission ratio to get the rpm numbers he's getting at 65 mph,whether it's 3rd or 4th is irrevalent,just getting it across to him,seems to be a bit difficult

 

[mtnrider]

Looking up your VIN you have an optional package, "2TG" which is a tow group and includes a 3.92 axle ratio if I am not mistaken. Optional packages will override the standard option (3.21) that is listed above that.

.

 

[Wild one]

Looking up your VIN you have an optional package, "2TG" which is a tow group and includes a 3.92 axle ratio if I am not mistaken. Optional packages will override the standard option (3.21) that is listed above that.

.

No matter how you punch 3.92 into the calculators,it doesn't match his original post,he's either at 73 mph using 0.75 or he's at 54 mph using 1.00. The only gear ratio that matches his original numbers is 3.21 in the 1.00:1 transmission ratio,as neither 3.55's or 3.92's will give him 2175 rpm at 65 mph,no matter what gear the transmission is in.
He could look for the sticker on the bottom of the drivers side axle tube,but on a 2010 there's a good chance it's either gone or is unreadable

 

[MudDog2007]

You aren't in 4th gear. Selecting 4th manually just sets the upper limit. Pull it down to third and I bet your rpm stays the same. If they increase you don't have a 321 rear or you have non standard transmission ratios.

Ok, it looks like the gear indicator is lying to me even when setting the gear from 1 and working up or 5 and bumping down.

Numbers yall are quoting appear appropriate for the speed and the gear stated but not the gear indicated. Like was said even though the 4th gear or 3rd for that matter it dosent mean its actually in that gear.

Also determining the 3.21 vs 3.55 by rotating the wheel is tough to be specific. The calcs do support the 3.21. My eyeball wanted 3.55 LOL

Case closed.

Unless somebody can tell me why the truck randomly when put in drive will go straight to 4th. Jump out and disconnect batt for a min and reconnect . Back to normal.

Subject for a different sub forum.

 

[Dean2]

Ok, it looks like the gear indicator is lying to me even when setting the gear from 1 and working up or 5 and bumping down.

Numbers yall are quoting appear appropriate for the speed and the gear stated but not the gear indicated. Like was said even though the 4th gear or 3rd for that matter it dosent mean its actually in that gear.

Also determining the 3.21 vs 3.55 by rotating the wheel is tough to be specific. The calcs do support the 3.21. My eyeball wanted 3.55 LOL

Case closed.

Unless somebody can tell me why the truck randomly when put in drive will go straight to 4th. Jump out and disconnect batt for a min and reconnect . Back to normal.

Subject for a different sub forum.

Glad you figured it out. I can be a little AR myself so I really do get it. Stay well, this is a great place to hang out and learn.

 

[Wild one]

Ok, it looks like the gear indicator is lying to me even when setting the gear from 1 and working up or 5 and bumping down.

Numbers yall are quoting appear appropriate for the speed and the gear stated but not the gear indicated. Like was said even though the 4th gear or 3rd for that matter it dosent mean its actually in that gear.

Also determining the 3.21 vs 3.55 by rotating the wheel is tough to be specific. The calcs do support the 3.21. My eyeball wanted 3.55 LOL

Case closed.

Unless somebody can tell me why the truck randomly when put in drive will go straight to 4th. Jump out and disconnect batt for a min and reconnect . Back to normal.

Subject for a different sub forum.

Glad you got it figured out. As far as your transmission issues,hopefully Burla will chime in,as he's up on the RFE issues more then most.

 

[MudDog2007]

Thanks for all the input. Yeah Im Old and stubborn.

This whole thing started as I just bought a 5000 lb camper and did some trial trips up and back on I10 and was rather concerned about what I saw rpm wise, not to mention coolant and tranny temps.

Fixed those with Larger Rad, Oil cooler add, Trans cooler add and a new WP with a 160 Tstat.

When I see 2700 rpm at cruise of 65 in Tow Haul mode I was kinda freaking out.