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Performance Upgrades - Maintenance - Modifications - Problem Solving - Off-Road - Street Trucks. Covering the Explorer, ST, Sport, Lincoln Aviator, Sport Trac, Mercury Mountaineer, Mazda Navajo, Ford Ranger, Mazda Pickups, and the Aerostar. Featuring H.I. - Human Intelligence.
How much did you pay for the 3.73 duffs from the salvage yard? I just want a rough estimate of that. 3.73s are better than 3.55 with 265/75
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Ronin paid $500 for front and rear 3.73 diffs. I just got quoted $850 for for front and rear 3.73 stock diffs with limited slip in the rear. For that kind of money, you might as well spend the $1450 and get gears that will last longer than the truck.
EDIT: Another thing...if you are starting with 3.55 diffs then you'll need to swap to a 3.73 carrier also when you regear. I regeared a set of 3.73 front and rear diffs that I got from the salvage yard so I didn't have to swap carriers.
This is only true for the front. There is no carrier break for the 8.8 reaguardless of the vehicle. As for the Dana 30 3.54/3.55 and down and 3.73 and up is the break. A good place to hunt for front diff parts would be the jeep sites to score used stuff.
Hi all, I'm ready to spend on bigger tires now but I definitely want to change my gear ratio to at least 3.73 from 3.55 to don't affect my mpg much. I know that the increment should by 2 but my budget only allows me one.
I just want to confirm that getting the diff from a junkyard just like Ronin did will be enough. Since English is not my first language, I tried reading this several times but the word carrier is killing me. If the carrier is the same as "pumpkin" then I know what to look for. I've seen some diff in 200 rear and 200 front so I think that is a fair price, right? Also just to clear one doubt, (just don't yell at me), if I change the rear to 3.73, I must do the front as well correct?
Thank you in advance for any comments and btw Ronin sorry to hear about your accident, those rock sliders looked awesome but the best thing is that no one got hurt and that the Ironman came fast to replace your lost.
Going to 3.73 is better than nothing. "Carrier" refers to a part inside the differential (or "pumpkin"), but I have noticed sometimes a differential is listed as a "carrier," so that might explain the confusion.
200 is a fair price for a used one if it is in good condition and doesn't leak oil. You may still want to replace some of the seals just to be safe.
Yes if you replace the rear with a 3.73, you must replace the front with one also.
Good luck and post if you have any more questions.
Hi all, I'm ready to spend on bigger tires now but I definitely want to change my gear ratio to at least 3.73 from 3.55 to don't affect my mpg much. I know that the increment should by 2 but my budget only allows me one.
I just want to confirm that getting the diff from a junkyard just like Ronin did will be enough. Since English is not my first language, I tried reading this several times but the word carrier is killing me. If the carrier is the same as "pumpkin" then I know what to look for. I've seen some diff in 200 rear and 200 front so I think that is a fair price, right? Also just to clear one doubt, (just don't yell at me), if I change the rear to 3.73, I must do the front as well correct?
Thank you in advance for any comments and btw Ronin sorry to hear about your accident, those rock sliders looked awesome but the best thing is that no one got hurt and that the Ironman came fast to replace your lost.
Thanks Ronin for your quick responses, this definitely helps me a lot.
Just another question, what seals should I replace when swaping the 3.73 diff in?
I already replaced one seal that goes from the diff to the axle (one that is very common) but are there some more inside of the differential that I would need to replace?
Thanks Ronin for your quick responses, this definitely helps me a lot.
Just another question, what seals should I replace when swaping the 3.73 diff in?
I already replaced one seal that goes from the diff to the axle (one that is very common) but are there some more inside of the differential that I would need to replace?
Really the biggest one would be the axle seals that you mentioned. The pinion seals sometimes leak but those are not too hard to change with the differentials installed in the truck. So if they aren't leaking on the replacement differentials, you can probably wait on those.
Two more things to keep in mind:
EDIT: If your truck has traction control with RSC you SHOULD be able to use a rear diff from either a truck with traction control OR one without it. The ABS sensor and tone ring for the NON-traction control vehicles is part of the diff itself...you just won't use that sensor if you have traction control since your ABS sensors are in the rear wheel hubs and your tone rings are on the ends of the CV axles. Now if you are a non-traction control truck, you will need a differential that is from a NON-traction control equipped truck, otherwise you won't have anywhere to hook your ABS harness up to.
After the swap, the computer in your truck will still think you have the stock 3.55 differentials, so your speedometer will be inaccurate and the transmission may shift in an odd way. Your computer will need to be reprogrammed for the new 3.73 ratio. This can be done with a tuner like the SCT XCal 3 (apparently the dealer can't do it as I had previously thought)
Really the biggest one would be the axle seals that you mentioned. The pinion seals sometimes leak but those are not too hard to change with the differentials installed in the truck. So if they aren't leaking on the replacement differentials, you can probably wait on those.
Two more things to keep in mind:
If your truck has traction control with RSC you will need a rear diff from a truck that has that same function.
After the swap, the computer in your truck will still think you have the stock 3.55 differentials, so your speedometer will be inaccurate and the transmission may shift in an odd way. Your computer will need to be reprogrammed for the new 3.73 ratio. This can be done by a ford dealer or with a tuner like the SCT XCal 3.
Great, so I will make sure that I don't get any diff that could be leaking...
I don't have traction control RSC, but thanks for the tip... I will make sure that I don't get one diff that could have this.
So I will need to reprogram it, no matter if I have traction control or not, right? I'm wondering how much would it cost this on the Ford stealership...
Great, so I will make sure that I don't get any diff that could be leaking...
I don't have traction control RSC, but thanks for the tip... I will make sure that I don't get one diff that could have this.
So I will need to reprogram it, no matter if I have traction control or not, right? I'm wondering how much would it cost this on the Ford stealership...
Yes you'll need the reprogram regardless of the traction control. It might be driveable without it but as I said your speedometer will be incorrect and it might shift in a weird way. A tuner like the one I mentioned costs $389 from Hensonperformance.com.
Yes you'll need the reprogram regardless of the traction control. It might be driveable without it but as I said your speedometer will be incorrect and it might shift in a weird way. No idea what it would cost at ford but I can't see it being more than an hour's worth of labor...shouldn't be more than $100. A tuner like the one I mentioned costs $389 from Hensonperformance.com.
Fyi ford dealers cannot reprogram your speedometer ,,,I just asked,they can't even change a rear axle ratio legally thanks to the clean air act of 2002 ,it would make it so our vehicles no longer meet epa certification
Me too...the dealers only 5 minutes away, really came as a shock to me ....
Plus they offer to reprogram my shift strategy but 05+ learns as to how you drive so itll slowly revert back unless you dog it...
Ugh time to call James for a tuner... This regear+add ls front and rear, is cresting $1200+ in parts(true trac$375 summit, gears $300 rockauto,trac lok carbon kit$107, tuner $389)...plus nothing has been installed yet....
Made some edits/corrections to my post #69 to clarify some bad/confusing info.
Fofopirata, since you have traction control, you SHOULD be able to use a diff from either a traction control equipped OR a non-traction control equipped truck. See my edited post above.
Thanks to Wills05XLT4x4 for pointing out where I was wrong on that.
Thanks to Wills05XLT4x4 for the good info and Ronin as well for editing your previous post.
I will call Ford here in my town (Tijuana Mexico) and see what they say, I know that there are some laws in the US that doesn't apply to Mexico (specially those that have to do with environment).
Btw, since I don't have any badge on my car aobut traction control, I do not think I have that. My X is a 2002 xls 4x4 that was built late that year. I remember seeing one of those things in my father in law 2006 X.
I just called to the service department of Ford and they guy told me that he is not aware of any reprogramming job after changing the differentials. I explained what I'm planning to do and he said that I just need to make sure that the crown of the pinion is correctly installed.
I don't know how much I can believe this guy but I will def keep looking into this.
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I had some problems with the 4x4 on my old 2000 and ended up buying a transfer case and the front diff. I never ended up installing the diff as the transfer case fixed the problms. I think I payed like $25 extra for the diff.
My question is, can I use the carrier from this diff (I think it's 3.73 LS) to swap to 4.10's in my 2003? If I am reading things correctly, I won't need to change the carrier in the rear, just the ring and pinion.
