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Discussion Starter #1 (Edited)
Bought a 97 4.6 used really nice car feel like something might have been done to it at 70 miles per hour the RPM steady at 2500
I'm only counting 3 shifts total from a dead stop
Is thia trans a 4 speed ? wasn't sure if I may have a stall converter or a 373 gear just seemed high rpms for highway speeds
Was making sure od is working like almost if it seemed like I had only 4th gear but when I disengage the od button it downshifts so all must be good. 50mph is around 1800 RPM and that's when it's already in od.
Then 2500 rpm at 70mph speed what would anyone guess I have going on here.

It's hard to say I doubt it's a stall but it could be geared
 

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Bought a 97 4.6 used really nice car feel like something might have been done to it at 70 miles per hour the RPM steady at 2500 wasn't sure if I may have a stall converter or a 373 gear just seemed high rpms for highway speeds
Was making sure od is working like almost if it seemed like I had only 4th gear but when I disengage the od button it downshifts so all must be good.
Is 2500 normal for a 70mph speed what would anyone guess I have going on here .
Car shifts into 2nd gear pretty quick around 1000 rpm 3rr to 4th gear shift is oddly fast though .
It's hard to say I doubt it's a stall but it could be geared
If factory sized tires, it's probably about right for a 3.27 which wasn't that uncommon for the 1997 4.6s.

What is the axle code on the door plate?

RwP
 

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Reading that was excruciating.

A stall would not affect hwy RPM as it would be locked up. You never did mention tire size, but if the speedo is correct, you likely have 3.73's in there. You can check by jacking up the read and rotating the driveshaft one full revolution, and see how many revolutions the right tire turns.

I can't tell you exactly what 70 MPH turns with 3.27's because I rarely drive that exact speed, but it's around 2000, with 26.6" dia tires. That's why I said 3.73's.

Al
 

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If you really are at 2500rpms at 70mph, you have 4.10s. 2500rpms with 3.73’s would be 75, and with stock 3.27 gears, it would be 86mph.
 

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If you really are at 2500rpms at 70mph, you have 4.10s. 2500rpms with 3.73’s would be 75, and with stock 3.27 gears, it would be 86mph.
I may disagree with that; I get an indicated 2500 at about 82 or so with 3.08s.

(Indicated, now ... and on an AOD, so it may be a bit higher than a truly locked up 4R70W would be.)

RwP
 

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Discussion Starter #7
If you really are at 2500rpms at 70mph, you have 4.10s. 2500rpms with 3.73’s would be 75, and with stock 3.27 gears, it would be 86mph.
215 70 15 tires stock wheels
And yea it is exactly 2500 at 70mph

I had thought over drive wasn't working and I was just winding out the rpms. It isn't bad but if I have 4:10s that's a bonus . The car seems like someone did some stuff at some point it has dual flows which are rotting and the rear diff cover leaks some maybe it had gears put in by a back yard mechanic.
 

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Discussion Starter #8
Bought a 97 4.6 used really nice car feel like something might have been done to it at 70 miles per hour the RPM steady at 2500 wasn't sure if I may have a stall converter or a 373 gear just seemed high rpms for highway speeds
Was making sure od is working like almost if it seemed like I had only 4th gear but when I disengage the od button it downshifts so all must be good.
Is 2500 normal for a 70mph speed what would anyone guess I have going on here .
Car shifts into 2nd gear pretty quick around 1000 rpm 3rr to 4th gear shift is oddly fast though .
It's hard to say I doubt it's a stall but it could be geared
If factory sized tires, it's probably about right for a 3.27 which wasn't that uncommon for the 1997 4.6s.

What is the axle code on the door plate?

RwP
Axle Code w5 but still 2500 rpm at 70 and builds about 500 rpm for every 5mph
 

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Rear end swapped out maybe?

I'll add my 2 cents! :D With the stock 3.27s and stock tires I was running 2000 rpm at 70 mph, now with the 3.73s and stock tires I'm running 2500 at 70 mph.

Joe
 

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Discussion Starter #10
Rear end swapped out maybe?

I'll add my 2 cents! <img src="http://forums.tccoa.com/images/smilies/vb2_biggrin.gif" border="0" alt="" title="Biggrin" class="inlineimg" /> With the stock 3.27s and stock tires I was running 2000 rpm at 70 mph, now with the 3.73s and stock tires I'm running 2500 at 70 mph.

Joe
Oh well it's either 373 or 410 I'm getting diff opinions not that it matters it's a stock motor but still nice . If I ever wanna figure out I can just pull the diff cover and look at some gear stampings if visible ?
Or how does the spinning drive shaft trick work to tell ?
 

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Here is the website I use to calculate effects of gear changes.
Top Speed Calculator
4R70 gear ratios are 2.84, 1.55, 1, and 0.7. Put those in for gears 1 through 4, put in your cruising rpm, and your tire size, and gear ratio, and it will tell you what the vehicle speed will be at those rpms in each gear. Putting in 2500 rpms, with 4.10s, stock tire size, and 4r70 gear ratios gives you exactly 70mph. Assuming your speedo and tach are correct, that car has 4.10s. First thing I would do would be to verify the speed with a gps. If that is correct, I would hook up a scan tool to check the tach reading against rpms according to the computer.
 

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...
I'm only counting 3 shifts total from a dead stop
...
First shift is ~12mph, and shifts to second.

Second shift is about 25, and is to 3rd.

My 4th gear shift is at 40mph.

That's three shifts, right?

:surprise:
 

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Discussion Starter #13
...
I'm only counting 3 shifts total from a dead stop
...
First shift is ~12mph, and shifts to second.

Second shift is about 25, and is to 3rd.

My 4th gear shift is at 40mph.

That's three shifts, right?

<img src="http://forums.tccoa.com/images/TCCOA_2015/smilies/tango_face_surprise.png" border="0" alt="" title="EEK! Surprise!" class="inlineimg" />
Im used to od as being 5 gears 5 speeds
My fault wasn't aware 4r70w is 4 speed and 4th gear ratio is considered od.
 

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Do Not, under any circumstances, do a wot shift to 4th. :)

4th is "Special" in these trannys, where there's a race condition on the Direct Clutch vs the Intermediate Clutch.

If you win, you can break the intermediate shaft into Three Pieces, which is very hard to do.

A 4th to 2nd shift is also discouraged; unless it hits 3rd first, it breaks ****. :)

You really should read some of the stuff here...

:grin2:
 

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My 97 has 3.73 gears and 2500 RPM occurs at 74 MPH as indicated on GPS speedo. With the stock tune, the car hit the speed limiter at 90 MPH.
 

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This is a GREAT calculator for gearing.
Stock 3.27 geared 97 with 215/70/15 tires will be at 2000 RPM at 70mph in OD. 2850 in 3rd which is 1:1.

3.73's with stock gearing has 75 just short of 2500rpm, like 2480 or so.

Easy way to find out if you're in OD or not is to push the OD button when cruising at 70. If RPM's raise up, you were in OD. :D

That said, shift out of OD before flooring it. The OD bands don't like full throttle either when engaging or disengaging.
 
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