Random 4x4 question

[FORDF250HDXLT]

Did the D50s come with 3.54 gears tho? Seems rare
I might have missed it but what year is this rear axle from?

i think all 4wd trucks that you see with 3.55 gearing sport 3.54 (actual) gears up front.
as far as i know,this applies to all 4wd vehicles.1 point difference up front than the rear.

 

[FORDF250HDXLT]

Thanks for the info... I'm pretty sure the gears were stock from '94. I have the Dana 50's code, and it says 3.54...

I can have my local tranny guy do this job, but we're getting into snow season now, so I can't do it myself.

I'm completely inexperienced in this department. Would a simple ring/pinion gear swap in the rear differential to 3.55 do the trick? (assuming the Dana was never changed, and it's still 3.54...)

as i am as well.as i understand it,it's just as simple as changing the diff in a 9" rear in that the whole pumkin can simply be pulled and set a whole new one in.in other words,quickly and easily....so long as you consider pulling axles "easy" lol!
but no tools and measuring requiring.swap the whole center and go.

oops.my bad.i misread your question.i answered as to change the front.you asked about the rear.
to change the rear (if your SRW,as for expense) it's far cheaper to just swap the rear axle if your looking for 3.55's (or 4.10s) because axles are cheap and to change gears in the rear sterling,R&P are required.this costs far more than a couple hundred dollar used axle because it requires time,tools,experience and skill.......or it wont last.

 

[crash-harris]

I've always preferred to swap just the gears. A bit more expensive, but when you factor in unknown conditions of bearings and seals, it about evens out. I like the piece of mind of keeping the bearings that I know are good and seals that I know don't leak. I always end up wanting to replace all those parts on axles before I roll them under the truck. There are plenty of write ups online on how to easily swap gear sets yourself.

 

[Waystro]

i think all 4wd trucks that you see with 3.55 gearing sport 3.54 (actual) gears up front.
as far as i know,this applies to all 4wd vehicles.1 point difference up front than the rear.

Interesting looks like I'll be doing some research.

 

[N.E fjord-by-fjord 2fiddy]

So, after I got the email from Alabama saying that they sent me 3.55's (literally, the text of the email was "3.55"... nothing else...), I went out and looked at the axle. IIRC, it came off of an 89 F350 7.3... So I assumed it was a 3.55 Sterling... I can't find a code tag on it anywhere. Since I already had an axle swapped in, and it was purported to be a 3.55 set, i am not going to be doing that again. I think I'm going to call the guy who did the axle for me, and ask if i can bring her in and look at the gears with him. If they were swapped already, and aren't 3.55, I'll get a 3.55 ring and pinion and have him put them in...

But if we get that diff cover off, and the ring gear says it's a 3.55 ratio.... Then what in the hell would be causing those tires to bind up? ...and only at every 1 1/2 rotation? Could it be a sloppy t-case? I would think that a t-case issue would be seen/felt up front, not in back... But again... I'm no expert.

Anyway, all this will have to wait til next week. I have to drive her to northern VT for a job i'm doing tomorrow morning. She'll have to run like she's running til I get back.

 

[N.E fjord-by-fjord 2fiddy]

...just found this online:

Yukon Gear FORD 10.25- 3.55 Ring and Pinion (Tech Note: Vehicles 1992 and older will require a new pinion yoke for this gear set, this corrects for the difference in the Short pinion vs the Long Pinion 10.25)

So, if I replaced a '94 10.25 rear with an '89 10.25 rear, does this detail possibly explain the binding? Also, if I got a new 3.55 set, would I have to get that new yoke? I'm getting even more confused... :/

 

[dunk]

No. Gear ratio is gear ratio. Short vs long pinion refers to spline length on the pinion gear and yoke. The shorts wear out and wobble, eventually self destructing the differential if let go long enough. If you now have a short pinion axle and a gearing mismatch, change the short pinion gears to new long pinion gears to match the front ratio. Short pinion Sterlings suck. I have a set of solid spacers in mine to eliminate the crush sleeve and it seems to be holding for now... Though eventually need to replace the gears and yoke as they are worn.

Reading material: http://www.fourwheeler.com/how-to/transmission-drivetrain/129-0506-ford-1025-1050-inch-axle-tips/

 

[crash-harris]

Yes, all 4x4 axle ratios are a 10th smaller numerical number (a 10th faster rotation) in the front versus the rear gear set.

@N.E fjord-by-fjord 2fiddy a sloppy/stretched t-case chain can indeed cause your symptoms. If there is too much slack in the chain, the drive train will bind inside the t-case

 

[N.E fjord-by-fjord 2fiddy]

...something about that just sounds right...

 

[riotwarrior]

So, after I got the email from Alabama saying that they sent me 3.55's (literally, the text of the email was "3.55"... nothing else...), I went out and looked at the axle. IIRC, it came off of an 89 F350 7.3... So I assumed it was a 3.55 Sterling... I can't find a code tag on it anywhere. Since I already had an axle swapped in, and it was purported to be a 3.55 set, i am not going to be doing that again. I think I'm going to call the guy who did the axle for me, and ask if i can bring her in and look at the gears with him. If they were swapped already, and aren't 3.55, I'll get a 3.55 ring and pinion and have him put them in...

But if we get that diff cover off, and the ring gear says it's a 3.55 ratio.... Then what in the hell would be causing those tires to bind up? ...and only at every 1 1/2 rotation? Could it be a sloppy t-case? I would think that a t-case issue would be seen/felt up front, not in back... But again... I'm no expert.

Anyway, all this will have to wait til next week. I have to drive her to northern VT for a job i'm doing tomorrow morning. She'll have to run like she's running til I get back.

Do what I suggested previosly to check gear ratios...if you do as I said NO HARM will.come of it.

You likely have 4.10 fronts and 3.55 rear.

Just saying 2 people some chalk about 2 minutes work...Bob's yer uncle and you know *** is going on.

JM3.55/4.10CW

 

[crash-harris]

...something about that just sounds right...

Front wheels need to turn just a little faster so you can steer.

 

[hce]

Yes, all 4x4 axle ratios are a 10th smaller numerical number (a 10th faster rotation) in the front versus the rear gear set.

@N.E fjord-by-fjord 2fiddy a sloppy/stretched t-case chain can indeed cause your symptoms. If there is too much slack in the chain, the drive train will bind inside the t-case

Not exactly, it was about the cost and being closer matched in ratio did not make a difference. The mismatched ratios 3.92/3.89 3.54/3.50 3.54/3.55 are only due to dana making 3.54 ratio for the front and ford making either 3.55 for the rears ie 10.25 and 8.8 the 9inch was 3.50. Ford matched up the ratios as close as they could without tooling up for the exact gear ratio. Sometimes the lower ratio would be in the front and sometime in the rear. My 84 has identical ratios front to rear being that both front and rear are dana. My ranger has 3.73 front and rear. the old 62 has 3.92 dana in front and 3.89 9inch in the rear. The slight difference in ratios are considered less then the difference in diameters of tire due to air pressure, weight on axle and manufacturing differences. Final note the differences is very little 3.54 and 3.50 was about the biggest difference and the 3.54 is only 98.87% slower, or 100 revolutions per 98.87, more accurately 354 and 350 revolutions, 1/10 would be 100 and 90 revolutions respectively.