BLWN BUX

I want to chang my gears to 3:73 and have the Dana 36 rear end now.
I converted to a ZF6 and 6th gear is un-usable with my 3:07's.

I see a set of Dana 36, 3:73 on Craigs list for $50 / 24K Miles.

I havent found that "deal" on a 44 B4 I spend real money.

My Questions:

Are all the dana 36 gears interchangable?

Also

Are the higher ratios "weaker"

This is only a weekend driver. I will probably never put a set of slick's on it, but I am making 489 WHP.

Any input would be great

Kool88vette

I like your vert. I've got an 88 vert. Can you tell me about your roll bar?

Anyway back to the topic. You can order a thick gear that can be installed in your Dana 36. It will be a good time to rebuild your pumpkin. It should last OK if you don't race it. With a thick gear you cou;ld get some gear whine. Richmond makes a good gear.

Just want to say i'm a little confused. I read your profile. With 3.07s you say, "Absolutely will not hook-up in first gear." Why make the problem worse?

If you change to 3.73s you might not be able to hook up in second.

Also, I gotta ask this because it's killing me. How do you get that Vette passed the California smog *****? I failed because of a AFPR even though my emissions were clean.

anesthes

Why do you say that? When he's coming out of the box his wheel speed is too high, once they break lose race is over. Some 3.73s will reduce the flash speed of the wheels yet increase leverage out of the gates. My vette was all over the road with 2.59's, and sticks just fine with 3.54s.

Logically I see your point, more leverage might cause it to break loose, but I think his initial wheel speed is causing the problem.

-- Joe

Steve20

with a stock 95 6MT and stock 3.45 rear gears, I can use 6th on relatively level roads at speeds greater than 60mph. With an additional 200 hp and torque, why is 6th not usable?

vader86

You should be able to use any 3-series gear in the 3-series case.

CFI-EFI

WRONG!!!


Also WRONG!!!


Any differential with a wide enough spread of available ratios, uses different differential cases for a range of ratios. The difference in the cases is the location of the ring gear mounting flange. Because of where the OE made the case change, the cases are referred to a a "2 series" case or a "3 series" case. For the Dana 36, all the gear sets with ratios in the 2s, take a "2 series" case, and all the gear sets in the 3s take a "3 series" case. With some brands and models of diffs it doesn't always come out exactly even like this. Dana only made the 3.07 and a very limited number of 3.31 gears for the Dana 36 in the "3 series". Most D36s have 2 series gears. When the after market came along to offer the 3.54 and 3.73 (3.75?) gears that Dana didn't, they were offered with "thick ring" gears to allow them to be used on the more common "2 series" cases. I don't know, but one would have to research what ratios are available in the "thick ring gear" and normal, stock ring gear configurations. Dana and "normal" thin ring gear replacements require the proper case 2 or 3 series for whatever ratio they are. Thick ring gears are special, after market, 3 series gears made to fit a "2 series" case. Therefore, "You can order a thick gear that can be installed in your Dana 36. is false. A "thick gear" gear set cannot be installed on the OPs 3.07:1, "3 series" case. And "You should be able to use any 3-series gear in the 3-series case." is not true of thick ring gear "3 series" gear sets.

BLWN BUX,
I hope all the gory details haven't confused you, but it appeared they were needed. Make sure the "3 series" gears you purchase are of the stock, normal, "thin ring gear" variety for your stock, 3.07, "3 series" case.

RACE ON!!!

anesthes

Carrier is different between 2-series and 3-series. I'd like to see documented proof of the case being dimensionally different.

-- Joe

CFI-EFI

Once again...
The carrier and caps, the aluminum third member housing is NOT different between ratios. Why would it be? If you don't think the internal case, the posi case, the ring gear case, is any different, what do you think the purpose of a "thick ring gear" is? Why do you think the carrier part number doesn't change, but the internal case part number does change between two and three series ratios? You can get your own documentation from a parts break down. As usual...

RACE ON!!!

JimiHendrix

You da man CFI....btw....doesnt CFI stand for certified flight instructor? bbuuzzzzz

I dont see anything anywhere that says 2 and 3 series parts are completely interchangable. Why would you want to risk it anyway....would be an expensive mistake. Just my 1/2 cent...

anesthes

Bang your head all you want, it won't help you get any smarter.

I looked up the parts diagram in the FSM. What I refer to as a "gear carrier" is apparently called a "case", and what I refer to as a "case" is called a housing. So in fact, I was agreeing with your tech, but wrong in the terms. I personally think the FSM is wrong in the terms, as EVERYWHERE else it refers to the thing that hold the ring gear as the "gear carrier"

So why does all the aftermarket catalogs and books I have call it a "carrier" yet the FSM calls it a case?

http://gearmechanic.com/Camposite_ge...ferential.html
http://www.pirate4x4.com/articles/te...sta/Gear_Setup

Bang your head a bit more.

-- Joe

BLWN BUX

Kool:
Thanks for the complement, My roll bar came with the car, but you are the 5-6th person asking me. I often wonder if I should make up 20-30 and sell them here. I can't coment on smog. I just know when I open the door in the morning I see it in the vally and I don't know how it got their


Lowering my gear ratio should increase my torque multilication by about 20%. I am realing looking forward to what that will do for overall acceleration in 2nd though 6th.

This is a street car, and its street fast and fun, with wheel spin or not. I love it, and anybody else that has my kind of obsession.

It does not preform at the track.
If I wanted to race it I would go to the 44 and install DR's
I actualy got beat 1/8 mile by a stock C5 because of spin.
Not that a stock C5 is not fast(thay are), but I have spent a lot of money to go faster.

I can pull 6th gear now but: The headers ring my ears, and the MPG guage shows that I am actual burning more fuel. My cam is too big to pull a 1500-1600 RPM load efficiently.

CFI,

I appreciate the in depth descriptions, No I am not confused..
Detail what I came here for.

Question repmains:

Is the lower ratio weaker??

The pinion has less teath on a 3.73 Yes?

anesthes

The carrier is different, the spacing for the mounting flange.

I'm not sure why the FSM calls the carrier a case, and the case a carrier. A simple google search for '3-series carrier' will show you results of the part in question. An ebay search for posi carrier will do the same thing.

So when CFI said "The CASE is different" I thought he was referring to what every other shop owner (including me) refers to, the CASE/HOUSING/PUMKIN.

I can't seem to find any other data showing this. Just the FSM.. weird..

-- Joe

CFI-EFI

Probably because despite common interchange, and misuse of the proper terms, the FSM, which I didn't consult for this thread, apparently has it right.



Maybe shop owners "down East" use those terms in that manner. It can be, to a degree, partly a geographical dialect. However, to keep from confusing even the simplest of minds, I clarified what I was referring to by mentioning "Any differential with a wide enough spread of available ratios, uses different differential cases for a range of ratios." The differential case is the case that houses the differential. The differential is the part of the rear end that allows for the differentiation of the axle shaft speeds, as necessary for going around corners, where the outside wheel must travel farther than the inside wheel. For those unaware, the differential consists of the differential spider pinions, the side gears, the pin (or in many cases a spider, or cross) the gear thrust washers, and the differential case that houses them. In a conventional rear end, the ring gear is mounted to the diff case. For further clarification I said that "The difference in the cases is the location of the ring gear mounting flange.". The ring gear mounting flange is not a part of the carrier and caps, the carrier housing. If my detailed description wasn't clear enough, I apologize. I tried to "dumb it down" for the lowest common denominator. For some, the clearest, most detailed description isn't "dumb" enough. Sometimes my best isn't good enough. Sorry.

RACE ON!!!

Redeasysport

I don't want to hijack but my 2.59 is a 2 series correct? Thus if I wanted to re gear I would need a thick gear Correct? And does said gear cause gear noise as I have read about the "thick" gears?

Kool88vette

That is correct. I just went through this with my gears. I had the option of using a thick gear or changing the pumpkin. I bought a 3.07 pumpkin for $150.00. I had it rebuilt and installed.

Sorry for the bad advice to the poster. I thought when you upgraded to taller gears you used a thick gear.

So the poster has a 3 series and changing to 3.73s would not present a problem with gear whine. Is that correct?

Lichen

CFI-EFI. Thank you for your wisdom. This is the first straight answer that I have got on this subject in 6 years. I am a total mechanical doofus, but if I understand you correctly, I had a 2.59 and went to a 3.54. So I had thick gears installed in a series 2 carrier. Correct? If not, then I am still an idiot. No matter what your attitude, you have give me more good advice than anybody on CF. Thank you

anesthes

When doing a search on ebay for "differential carriers" I get exactly what I'd expect. (the thing you call a case).

When searching google, I get the same result.

When searching summit, I get the same result.

When reading auburn, and richmond literature it refers to it as a carrier as well.

http://store.summitracing.com/partde...5&autoview=sku


I don't know why the C4 FSM and you call the case a carrier and the carrier a case, but since I can't find any references to it your way anywhere else, I can't see how you could have possible not known what I was referring to in my earlier post.

I'd agree if google, ebay, summit, auburn, richmond, and a ton of other sites didn't back me up. If the FSM didn't agree with you i'd call you crazy.. I can't answer why some vendors/folks interchange the part name, but I doubt it's geographical.


Exactly, you clarified it by using terms that are used differently. "the differential case is the case that houses the differential". Yes, considering a carrier is sometimes called a differential, or a chuck, it sounds very much like you were calling the case the case. But then when you went on to say the case was different, how am I supposed to know you were referring to the carrier. Again, I couldn't find anything other than the FSM diagram that labels it that way.. Wonder why that is.

-- Joe

BLWN BUX

While you guys are pissing back if forth,
Does anybody know the answer to my last question?

Is the 3.73 weaker than the 3.07?

makn u shiver

The 3.73 for a d36 uses a thicker ring gear but a smaller pinion gear then the 3.07 so its kind of hard to say .but i will tell you one thing i think the d36 is totally understimated and is stronger then most think it is .The key to a a well built d 36 or d44 that will live under some power is a good gear set like us gear or richmond gears and most important is that the gears as set properly ,pinion depth,back lash and proper case and carrier prep and gear break in.I have built 3 dana 36 rears, 2 with u.s strange 3.73 gears and one with richmond 3.75 and so far they are still going good.One of them is behind a 4+3 vette with a 400 sbc miniram and he uses m/t slicks ,3 years so far.Mine a 383 stroker with a p600 blower and a 3200 stall and m/t street radials and it hooks great . Evertime i launch i think this is it I'm going to blow the rearend but i have been very surprised and my Buddy with the 4+3 has twisted half shafts but the rear is still good.You cant compare a d44 to a d36 of course the d44 is stronger but the d36 ain't as weak as some make it out to be .

Kool88vette

Makn U Shiver says "The 3.73 for a d36 uses a thicker ring gear" That's what I was told also.

So was I wrong when I said to use a thick gear?