Are you happy with your 3.55's?

[Jughead]

Are you happy with your 3.54's?

It looks like I am about to install 3.54 gears with my 93 A4 convertible. I honestly had a hard time deciding to go with them over the 3.08 but either would have been a vast improvement over the current 2.59 arrangement. I have had several locals express opinions about the durabilty of the 3.54's while others swear there will be no problems. What do you guys think and what feel about this choice? All feedback will be appreciated.

 

[aboatguy]

I used 3.45s (these seem to be the most common gear in a D44) and I could not be happier. I still get good mileage (it actually improve a little in city driving and I only took about a 2 MPG hit at 85 MPH highway cruising). I figured it was worth spending the extra couple of hundred bucks on a D44 over modding a D36 since I have long term modification plans for my corvette. I should have around 400RWHP by this time next month.

If your engine is close to stock the D36 should be fine, however, if you mod the engine and install sticky tires that is a different story.


Mike

 

[fredk]

3.54's and they are great!!!!!!!!!!!!! Not much different at 60 and they took 3/10's off my 1/4 mile times.

Fred

 

[grapeknutz]

3.54's and they are great!!!!!!!!!!!!! Not much different at 60 and they took 3/10's off my 1/4 mile times.

Fred

What was the RPM difference between the 2.59 and the 3.54?

 

[C-4 Now]

fredk what did you have before. I have been think about changing to 3.54's! Both my 89-6speeds have 3.33's Thanks Ike

 

[fredk]

I had 2.59's before. It now revs about 600 rpm's more at 60. The cost does not justify the results going from 3.36 to 3.54. The job is pretty labour intensive. If I remember right it was about 8 hours of labour.

Fred

 

[Doutdoor]

I put the 3:54's in my 92 LT1 and also love them. I did a lot of research on the gears and decided the 3:54's were the best choice. They give you much better acceleration over the stock 2:59 gears and also allow for good highway cruising at not too high a RPM. At 75 mph you're at about 3,000 rpm in overdrive. The thing I stress the most and have seen others stress is make sure you find someone who does the setup properly because it will make a difference in the amount of gear whine you get. A little gear noise is normal but you don't want it to be too noticeable. The guy that did mine set the gears up perfectly.

 

[Ramrod92]

I loved the switch from the 2:59s to 3:54s with the stock motor. Here's what my 396 w/3500 stall convertor did though.

If you ever plan to crank up the power, you'd be better off doing a swap to a Dana 44.

 

[Mad-Mic]

I loved the switch from the 2:59s to 3:54s with the stock motor. Here's what my 396 w/3500 stall convertor did though.

If you ever plan to crank up the power, you'd be better off doing a swap to a Dana 44.

did you flash stall it? i think a D36 with stock 2.59's are stock 3.07's can last if brake stall is applied. what happens is people get the wise idea to install a lower gear set. well this applies to physics but it doesn't apply to real world knowledge. what i mean here is this.

lower gears equal smaller Ring gear. with a Smaller Ring gear now you have less Gear overlap. with out that overlap now the gear set flexs the case and breaks. the flex causes the case to break in half. with the lower gears you get 1 pinion tooth fitting into 1 ring groove. with the stock configuration you have 2 pinion teeth fitting into 2 ring grooves. With strength the flex is minimal. this is why GM went with extra webbing in the D36 Batwing. Is it the end all know all? No obviously the D44 setup is a heavier unit but i'm at 385 rwtq now and beat the ever loving day lights out of mine and i'm only bolt on's. a friend of mine has an 85 vette with SR/ZZ409 cam/AFR 195 heads/383 stroker/3500 stall/MT ET Streets (slicks) with skinnies up front all on a 3.07 STOCK D36 rear with 100's of 1/4 passes on it.

why did is it lasting? Brake stalling on Bias Slicks. When you brake stall you are loading up the whole drivetrain unlike dropping the clutch and having sloppy play in the drive train. obviously the shock is harder even at the same RPM. this is why you see drag cars at the track when they stage the rear end raises up a few inches. they are brake stalling. we in the drag racing world call this "Loading the Rear" or Loading up the Rear. Do this on a Biased ply slick and the side wall gives and doesn't shock the drivetrain as hard as a drag radial with no sidewall.

basically it boils down to this if you want to race alot and plan to mod alot your racing on borrowed time. so to me it's simple i will not change a D36 gear set out. If and When it breaks I will use the Money I saved from doing a gear swap in the D36 which is about 1k+ and put that into a D44 with the gear set I want. If you want to spend the money for the gear swap then you are driving on Borrowed Time because that one time you nail it from a dig and a tire catches a bad spot on the road like a bump and unloads that rear and it loads again say Bye Bye. I don't know how many times i've heard this that people try to go the cheap route and just do a gear set even on a stock car. Will it work? Yes it will but if your like me and like to put your foot in it every once in a while it will break sooner or later with a gear set in a stock D36.

 

[speedmaster4]

mine came with 3.07 (its a man trans)...switch to 3.73 and first gear spun the tires everywhere...changed to 3.54 and its perfect for street

trans brake or ''neutral'' starts should be a felony arrest for murder of everything under the car

 

[Jughead]

Ok guys ...now you have me wondering. My LT1 will only be barely above stock so I wonder how many of you have destroyed your D36 with only minor bolt ons (catback, open lid, K&N and PCMforless) ? This thing will never be a HP or torque monster...just driven "spiritedly" on occasion.

 

[Mad-Mic]

really depends if you race alot. if it's a cruiser you'll be fine but if your like me and race alot then your on borrowed time. if you put a high stall in it and flash it real good and it shocks the drivetrain hard then you are asking for problems.

i can say with mild bolt on's i'm around 270 rwhp and close to 400 rwtq and mine is still good and i've beat the hell out of it for 50k in miles. this is all on a 2.59 gear though and i've stated the reason above why i won't swap out unless i do a D44.

 

[Jughead]

What about a change to 3.07's... or do it would be best to find a D36 with 3.07's pretty reasonable and just do a pumpkin swap?

 

[Mad-Mic]

What about a change to 3.07's... or do it would be best to find a D36 with 3.07's pretty reasonable and just do a pumpkin swap?

they are both pretty cheap but no matter what you are paying for labor and the labor is about 8 hours at 60+ an hour depending on where your at.

difference between a 3.07 geared car and a 2.59 geared car is less than .2 in the 1/4 mile

if you want more umph do some long tube headers. best bang for the buck