It hasn't been long since I posted my last question...and I am back allready
I was hoping to get some input on what ratio I should put in my truck..I have a 65 F250, 300 six, 3 on the tree...I am using 77 F100 power disc brakes on front and I would like to use the rear end out of the other truck I own (64 F100)...it has the 9" rear with a 3.89 ratio. I would like to bring the RPM down when cruising..... I have read others suggesting 3.25 or 3.50 (I was leaning towards 3.25's) would this work for my application? I will not be hauling anything with my truck, maybe a cooler and lawn chair
I have not worked on rear ends too much....would swapping the ring and pinion be something I could attempt myself??...(with help from friends of course)
A friend of mine suggested that I buy a "new" ring and pinion.....not get used out of another rear end..... I noticed LMC truck sells ring and pinion sets....anyone know where else I could get a set???
Collingwood? Very nice. Blue Mountain and my trick knee are old acquaintances.
Your line of questions is right up my alley. Similar to your setup, my F100, L6 240, 4-speed granny, 9-inch rear is set up with 3.00 gears.
3.89 is too high, unless you are pulling stumps or drag-racing. Assuming you have 26" tall tires you would cruise 3016 RPM at 60 MPH. Having just installed a tach in my truck the other day, I find out that the roar I heard from my engine when I shifted late for power occured at barely 3000 RPM. This engine sounds so tapped-out at 3000 that if I revved it to 3200, I swear I'd grenade it. I am used to cars and trucks of all eras, engines, trans and differentials, but I never would have guessed the shift point and noise to occur at such a relatively low RPM.
So, if you approach 3000 RPM upon cruising you probably won't be very comfortable, either.
Run some scenarios:
Ratio x MPH x 336 (a constant) divided by Tire diameter = RPM
Plug in different numbers in the ratio spot, the MPH spot, and the tire diameter spot (depending on your specs), and you'll get the RPM at whatever speed you plugged-in.
3.89 ratio x 60MPH x 336 / 26" tires = 3016 RPM
3.50 ratio x 60MPH x 336 / 26" tires = 2713 RPM
3.25 ratio x 60MPH x 336 / 26" tires = 2520 RPM
3.00 ratio x 60MPH x 336 / 26" tires = 2326 RPM
3.00 ratio x 70MPH x 336 / 26" tires = 2713 RPM
Only the last equation shows a different MPH. The first 4 are based on 60mph, and the last on 70mph.
I have heard it said that an engine working at 2400 RPM is working at its most efficient speed (Power vs/ Fuel economy). If you lowered the ratio below 3.00, you would feel like you were starting out in second gear, or could never shift into High until the freeway, where of course the opposite is true of 4.11 gears, where you'd shift from First half-way through the intersection, and could never hear you radio when on the freeway getting 8 mpg.
I find that since I am always fully loaded with about 750 lbs of tools, and cruising the speed limit at 70MPH, my setup cruises at 2433 RPM
3.00 ratio x 70mph x 336 / 29" tires= 2433RPM
I get 13-17 mpg this way, and typically 15 mpg. I know I need a tune-up, and my 1-barrel carb and 240CID displacement means not a lot of torque. I am switching to the 2 barrel Clifford Intake, Road Demon 2 barrel carb, and Clifford Ceramic Dual Headers. It is supposed to be good for a gain of 45% torque, about the same in Horsepower, and an impressive increase in MPG. As it is now, 4th gear for me on a grade is not powerful enough, but I don't loose too much speed. Shifting down to third however would mean listening to that 2900-3000 RPM roar that I never loved. So for me, increasing torque output is one of my only options.
You however, already have a torquey 300 CID L6. If I can cruise at 70, and pull strong from a light in 2nd gear with a 750lb payload (plus me), then you certainly have the power to do the same.
If you change from 3.89 to 3.50 gears, you will drop your RPM by only 10.02%
If you change from 3.89 to 3.25, your RPM drops 16.45%
If you change from 3.89 to 3.00, your RPM drops by 22.87%
The first gear swap (3.89 to 3.50) is such a small change that I believe it would be a waste, or I should say, a wa$te. When I went from 26" tires to 29" tires, I dropped 10.35% in RPM. Barely noticeable!!
I am happy with my 3.00 ratio. I'll stop short of saying "this is what you should do, too", because I know there will be varying opinions on the subject. 4.11 is cwaaaazy, and 3.00 is about as far as I'd ever go before suffering loss of power and economy. You sound like a good candidate for "highway gears", and sounds like you should have the power to exercise different options.
I would try to find a good used carrier with the ratio you are looking for . changing ring and pinion is very difficult without experience and tools and gauges to set up backlash and if you dont get it right you get a very loud whine and probably premature failure. if you have to go that route find someone who has the tools and kowledge to set it up for you
Dan - That's very cool you've been to Blue Mountain!! I am about 15 mins away....I love living here, besides all the snow we get (We just got a snow storm today) it's a gorgious area and the views are amazing
You posted alot of info and I really appreciate it! That formula for figuring out the RPM is great!! I take it from your post I should go with 3.00.....based on the RPM info I think it's exactly what I was looking for....
Well, since I lived in Mississauga for 11 years, and worked in automotive all that time, I have some local ideas for you. JMW Automotive in Kitchener deals in differentials, transfer cases and so on. They could take care of you easily. Barrie is loaded with shops that deal with transmissions, differentials, etc, and Russ at Simcoe Transmission in Barrie seemed to be a straight shooter with down-to-earth pricing. Carlo at Barrie Transmission is right next to Russ, and equally sharp (both on Simcoe Street). Marty at Mr Transmission in Collingwood would be a good resource. I used to sell to all these shops, and like Lowell said in the previous reply, it's a precision task to set up the preload, backlash and toe/heel pattern properly. Stick with a pro!! The nice thing about a 9" is that it is a "Pumpkin", and can be bench assembled, and you can put it in the housing yourself, install the axles, and there is little left for you to fuss with. Or, let a shop handle it, and you should have no worries.... not even dirty hands. Good luck. Dan
3:00 are a nice gear setup, I had them in a '78 302 F100 with an automatic and that sucker would get 20 Mpg on the highway, consistently, dead stock with a single exhaust.
A 300 six actually has more torque than a 302, so I think you will be good to go, although you are gonna have to slip the clutch a bit to get off the line.
Get the punkin set up by someone if you go for new gears, but to install the section is relatively simple, its like 10 nuts and a gasket, and them you slip the axles in. Not bad.
It's a race.. Will hell freeze over or will JC finish his truck first. Stay tuned..
I wasn't expecting that.....thank you for all of those references
I will definately check out the places you mentioned....BTW, I checked out your profile and saw the pics of your truck....very nice ....and I noticed you had some kind of spray in bed liner??? I am looking for a decent spray in bed liner that is fairly thick that I could use in my truck.... I would like to spray it myself if I could....just wondering what you used for your truck??
I recently went from 3.70's to 3.25's. Dunno the MPG difference yet, but I'm expecting a 1 or 2 mpg increase. I can feel the decrease in acceleration. The change at cruising speed is harder to tell; it's quieter but I think the 3.70's pinion bearing was bad which would've contributed to the noise.
I tried the "do-it-yourselfer" bedliner in a 72 Chevy C20 I restored (brushed and rolled-on), and the 65 F100 was about 6-7 spray cans of "Dupli-Color" spray on liner. I hate spending too much money for professionally applied Rhino Lining or similar, but I really hate wasting money on things that backfire. The phrase goes "You never have enough time to do something right the first time, but you always have time to do it over". Well, substitute the word "time" for "money", and it still rings true. Both the roll-on lining and the spray on linings failed miserably, and with the spray-on in the F100, the parts that peeled off in the wind did so easily. The parts that did not fall off would not come off with muriatic acid or 2000 psi pressure washer either. So, I should have gotten a Rhino liner, instead I got a Zebra liner.
The brush-on stuff when from shiny black to chalky dark gray, and the spray on simply sprayed off in places. Next time.... I'll go pro with Rhino or similar, but now I'll have to pay EXTRA for them to skin the rest of the hide off my zebra to get it to stick. Save your Loonies and Toonies, and get it done right. Keep us posted.
Thanks for the advice....I kinda wanted to do it myself to save some money...but if I'm going through all that work not to have it turn out very well and possibly cost more in the long run..........then I will save my pennies and get it done right.
I'll have to price out how much $$$ for a Rhino liner, I'm pretty sure there is some place in Barrie that does it.
Sounds like you are planning to replace the whole rearend, you will have 5 lugs all the way around. What rear end does your F250 Have now?
One thing to keep in mind when searching for the pumpkin. Your 64 will be a 28 Spline. New trucks 73(?) and up could be 28 or 32 spline. Also you may run into some diffrent size yokes.
Good Luck, I have thought of converting my F250 the same way.
I have a 73, 300, 3-speed F-150 with 3.00:1's in it. It is fine for cruising but I like to take off quick so I am going to swap to a 3.25:1 some time (when I find one). I am also looking at swaping in a T-5, then I might put in a 3.7 or 3.5
I would go with a 3.25 if I where you, due to the fact that you might want a little more in the hills.
MadMaxetc - It seems that, generally speaking, you won't feel a difference unless you increase / decrease axle gears by 0.5 or more. With a T5 and 3.5's I think you'd be happy with the better acceleration but still get the same or better MPG from that 5th gear.
[quote=Mazlem]...With a T5 and 3.5's I think you'd be happy with the better acceleration but still get the same or better MPG from that 5th gear.[/quote]
The only reasion I would go with the 3.70:1 is cuz it in sitting in my garage right now.
I would have to put the truck down for a few weekend to do the swap (I am lazzy and takes me a long time to do stuff) so it will have to be done next year.
Now Dan - that is about the best info I ever read on a rear ends - thanks alot.
I have a 262-6 - and try it with a 411 Dana Spicer. I will do the calc on the rpms - but I dont' get it over 50 mph - and right - I am out of second (I skip the first one - the granny) before I am through the intersection- I am in 4th by 25 mph.
I swear I could pull a house off the foundation if I had the traction.
I haul alot of dirt and compost in mine - so I might go with 3.25 or 3.50. Should I find a punkin axel in a yard? or buy the rings and pinions from Randy's and have them installed in the Dana?
what would you do??
Monty
Monty (that's funny, Montgomery is a family name of mine, and I have been called Monty),
The Dana Spicer is an awesome piece. With my Dana 60 I had 4.10 gears. Since I had an overdrive, 4.10s were great. The lower than normal 1st gear transformed the 4.10 into 4.97s at takeoff, and the overdrive 4th made my 4.10s into 2.87s at cruising speed. Pretty cool for overall low-end and top-end.
If I had not had the overdrive, I would have never stayed with the 4.10 ratio. I can't stand the poor fuel economy, and I didn't need all that low-end..... I was cruising for the most part. With the Dana 60, the only other options I had were 3.54 or 3.73. I did not find the potential 13.65% decrease in RPM (with the 3.54s) to be worth the time or expense. Without overdrive, the 4.10s would rev 3444 at 70mph, and switching to 3.54s would only bring that down to 2973rpm..... still too high for my taste.
So part of my confusion is, can you get 3.25s or 3.50s for your intended swap? Are you talking about Dana 44, Dana 60 or switching to a 9" to accomodate your switch to 3.25s??
Regardless, since you skip first gear now, it tells me that you have at least that much untapped potential. Since your 4.11s are already so low, you don't need 1st gear currently. But, if you change to 3.25s or so, you may find that you want to or need to use granny 1st more often, but when you get to 4th gear, you will be revving 20.92% slower than you were before with 4.11s, and you'll find that your 50mph top end is more like 63.23mph with the 26.46% difference you created with the gear swap.
I have always felt that New is best when it comes to ring and pinions, and almost everything else for that matter. If you can find the ratio you want New, then that sounds like the best avenue.
i love my 4.56. front and rear.wish all you guys knocking the 4.11, 4.56 and 4.88s would drop them off in my yard if you dont want them and ill give you some 3.50s i dont want.
i go 75 mph in my 66 f250 4x4 ,4.56 with y block,all the time, no problem.i had a 65 f350 with 4.88 and FE engine that i took up over 100 mph.
i can climb the face of a cow, and pull you sideways behind me all the way up.
to each his own, i like the low end gears.
1966 F250 4x4
1964 Rambler Ambassador 990
Rest in peace departed Slick family members
Cam Milam
Lesley Ferguson
Steve Lopes
John Sutton
Iceman,
You summed it up..... "to each his own". 4.56 and 4.88 sound like they are right up your alley. If I had any sets of them, I would drop them off to you. I have never had an FE, nor have I ever needed the torque capacity to "climb the face of a cow". My straight 6 does what I need it to do. I have heard it said the L6 240 in granny low produces 1000 ft lbs of torque. If that is true, I bet you've got over twice that torque.
1000 is enough for me and my medium duty, high mileage use. In the "land of the midnight sun", however, there probably is no such thing as "medium duty". You have to go all out to survive, right? So, the bigger the better; there is no substitute for Heavy Duty in extreme environments, right? I know it's not 24/7/365 permafrost there, but you certainly have much greater demands on yourself and your vehicles than we ever will in Southern California.
I know I can go 80 mph or so in my F100 at 2780 rpm. I have only had a tach in it for a week or two. I notice that 3000 RPM is about all it can handle. Above that, it sounds like it's gonna blow. Your FE must have a much higher redline, and must be music to your ears at 100 mph. That's 5850 rpm at 100 mph with 28" tall tires?? Holy smokes. I know I couldn't rev that high without nitrous and a hurricane for a tail wind. Keep on truckin'.
As for me, I sure won't "knock" anyone for their choice of anything, be it L6, FE, Dana, Ford 9", AOD, NP or even Chevrolet vs. Ford. For every guy like me who loves his highway gears and overdrive, there is someone else who loves 4.88s and low range in the transfer case. Me and my fair weather F100 are cruisin' the SoCal highways, looking for ways to improve our cruise. I'll leave the severe duty stuff to my much heartier neighbors to the north.
Dan, my 66 with 292 y - block, 4 speed warner trans and 4.56 turns 2900 @ 70 mph with 265-85-16 tires.summer tires were 9.50 16.5 turned a little more rpms.
the f350 with 4.88 sounded like the concorde jet @ 100 mph.never got a chance to try out the 5.13 rear in the 64 f350 i had before i parted it out.sold the frame and rear end to a friend who needed a frame for a studebaker truck he has
my wifes 66 f 100 4x4 has a FE, np 435 and 3.50 gears.it really moves and i cant keep my foot out of it.
1966 F250 4x4
1964 Rambler Ambassador 990
Rest in peace departed Slick family members
Cam Milam
Lesley Ferguson
Steve Lopes
John Sutton
That formula for figuring out the RPM is great!! I take it from your post I should go with 3.00.....based on the RPM info I think it's exactly what I was looking for....
so I am going to swap to a 3.25:1 some time (when I find one). I am also looking at swaping in a T-5, then I might put in a 3.7 or 3.5