|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
08-13-2019, 06:11 PM | #1 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
5 spd in a 37 pickup with a 4.44 rearend.
What will my rpms be at 55mph? I'm running 15" radials. 6.75 R 15. Wondering if it will help. 5spd is a 1985 S-10. Thanks agian for the help, Jim. [email protected]
|
08-13-2019, 06:26 PM | #2 |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
RPM equals MPH times the Transmission Gear Ratio times the Rear Axle Ratio times the constant 336 all divided by the Tire Diameter.
RPM = (MPH X TGR X RAR X 336)/TD You know the tire diameter size you are using so you can look up the diameter. You know the MPH you want the RPMs at, 55. You need to determine the Overdrive gear ratio for your transmission. You know the Rear Axle Ratio, 4.44. So, RPM = (55 X TGR? X 4.44 X 336)/ TD? I don't see a 6.75 tire, but a 6.70-15 radial is 28.24 inches. Assuming a V6, the OD ratio of a 1985 S10 T5 should be 0.70 (think that should be 0.72) RPM = (55 X 0.70 X 4.44 X 336) / 28.24 RPM = 2034 RPM If my math is correct, 2034 RPM Last edited by JSeery; 08-13-2019 at 09:19 PM. |
Sponsored Links (Register now to hide all advertisements) |
|
08-13-2019, 08:37 PM | #3 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Wow. Thank you so much. The engine the t-5 came frome was a 1985 S-10 4 cylinder. Same ratio? Thanks again. Jim.
|
08-13-2019, 08:38 PM | #4 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Your tire size is right not mine sorry. Jim
|
08-13-2019, 09:00 PM | #5 | |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Quote:
Last edited by JSeery; 08-13-2019 at 09:11 PM. |
|
08-13-2019, 09:03 PM | #6 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Sponsored Links (Register now to hide all advertisements)
|
08-13-2019, 09:18 PM | #7 |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
I'm finding conflicting data just using year and engine type, the tag number would nail it down. The attached chart gives some of the tag numbers.
|
08-14-2019, 05:45 PM | #8 |
Senior Member
Join Date: May 2010
Location: East Shore of LAKE HOUSTON
Posts: 11,113
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
If that is indeed an S-10 trans, it's more than likely that the 1st gear ratio is going to be 4.03. I'd be more concerned that by combining that 1st gear ratio with a 4.44 rear end would just about make 1st gear useless. DD
|
08-14-2019, 05:46 PM | #9 |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Yep, but can always drive it as a 3-speed with OD. I much prefer the Ford Cobra and later Chevy gearing (close-ratio), with a low rear axle gear.
|
08-14-2019, 05:51 PM | #10 | |
Senior Member
Join Date: May 2010
Location: East Shore of LAKE HOUSTON
Posts: 11,113
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Quote:
I absolutely agree with the close-ratio derivatives. Even the EARLY Chevy and Ford gear sets had the 2.95 1st gear (close-ratio). DD |
|
08-15-2019, 08:31 AM | #11 |
Senior Member
Join Date: Apr 2014
Location: Minnesota
Posts: 1,166
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Here is a handy calculator to figure RPMs. When I actually checked mine with a tachometer it was spot on with the calculator,
https://www.crawlpedia.com/rpm_gear_calculator.htm |
08-15-2019, 07:58 PM | #12 |
Senior Member
Join Date: May 2010
Location: Williamsburg, Virginia
Posts: 2,654
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
These trannys are really simple units and different gears are available for first and such - you can try Ed Harnett in Maryland as he might be able to provide you with a decent gearset that would match your combo well. The tag would really tell the story but if there is no tag, and indeed the tag might not be correct, you can run through the gears and count the revolutions to come up with a good idea on what you have presently.
BTW, 55 mph at 2000 rpm isn't bad - your 5th gear ratio should be around 2500 at 75 MPH - that would give you plenty of power for the hills with that 4.44 rear gear I think. Reagardless, have fun doing it - you will not regret it IMHO ..... |
10-03-2019, 09:27 PM | #13 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Got it in. Now to get rid of the vibration in the driveline. The shaft is balanced and U joints are okay. New slip yoke and bearing going in. LOVE that T-5.
|
10-03-2019, 11:29 PM | #14 |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Are the angles and phasing correct between the transmission, driveshaft and rear axle?
|
11-02-2019, 08:36 PM | #15 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Checked with laser and it's right on. Reballanced driveshaft third time. Much better but still can feel it between 51 and 58mph. When below or above it's gone unless you push the clutch in and it really vibrates slowing down and disappears again at 25mph. What in heavens name is going on. I love this setup otherwise.
|
11-02-2019, 08:39 PM | #16 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Oh BTW. I a m using a gps for speedo accuracy. Still need to figure an new gear for tranny.
|
11-02-2019, 08:53 PM | #17 |
Member Emeritus
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Has the flywheel and clutch assembly been balanced?
|
11-02-2019, 11:10 PM | #18 |
Senior Member
Join Date: May 2010
Location: Chester Vt
Posts: 8,860
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
Just think of the burn outs he can do in 1st, just light em up!!
|
11-03-2019, 02:02 AM | #19 |
Senior Member
Join Date: Jul 2019
Location: Southern Oregon
Posts: 782
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
A lot of times, you'll get that type vibration, when the tail shaft bearing is warn. The front yoke to tail shaft bearing.
__________________
Frank '35 Ford Model 51 '48 Ford F3 '54 Ford Tudor Mainline |
01-11-2020, 09:41 PM | #20 |
Member
Join Date: Jul 2014
Location: orrington, maine
Posts: 89
|
Re: 5 spd in a 37 pickup with a 4.44 rearend.
New bearing in tail shaft, no difference.
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|