Dana 36 upgrade?
Thread Starter
Intermediate
Joined: Nov 2023
Posts: 27
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From: Utah
Dana 36 upgrade?
I have an ‘86 and I need to get rid of the 2.59 in the back. I want to upgrade to a Dana 44 but I have a few questions. I know there are quite a few of different Dana 44s but are they similar at all? Can I get a Dana 44 and put a batwing on it? What should I do to upgrade my rear? The cheaper the better to.
Thread Starter
Intermediate
Joined: Nov 2023
Posts: 27
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From: Utah
Team Owner
Joined: Sep 2003
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D36 3.07 was used all years but if you were shopping for an assembled one you would like to confirm it's '85 or newer. There was a change in the differential pinions shaft retention and many 84's wouldn't have had. Post a WTB here in the C4 section mentioning your location. Many are shopping the same thing but they're often found. eBay yes but you need to maybe be very cautious. There are vendors that offer them also as rebuilds.
Burning Brakes
Joined: Nov 2004
Posts: 1,193
Likes: 176
From: Hillsborough NC
I swapped out the 2.59 in my 86 convertible for a 3.07 D36 unit from a 92 and it worked flawlessly. Retained my batwing and all other mounting hardware.
Be sure to do a search for the correct speedo drive gear combination for your transmission (Mine is an Automatic). That was actually the hardest part, verifying what gears were needed and then finding them to purchase. They can be found (found mine on eBay) but their current owners do seem to be proud of them.
It is a very nice improvement with little effect on the mileage IMO and if you have a stock or close to stock motor, the D36 should be tough enough.
Be sure to do a search for the correct speedo drive gear combination for your transmission (Mine is an Automatic). That was actually the hardest part, verifying what gears were needed and then finding them to purchase. They can be found (found mine on eBay) but their current owners do seem to be proud of them.
It is a very nice improvement with little effect on the mileage IMO and if you have a stock or close to stock motor, the D36 should be tough enough.
Drifting
Joined: Feb 2017
Posts: 1,274
Likes: 399
From: Tacoma WA
2024 C4 of the Year Finalist - Unmodified
XanBarclay07, your profile does not mention where you are located but if you are close I have a 3:07 out of a 92 that has about 40,000 miles on it that I would be willing to sell. With current shipping rates shipping might be too costly.
Advanced
Joined: Jan 2021
Posts: 74
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From: NE Ohio
While we are talking about the Dana 36 on what I assume to be a L98/TH700R4 combo C4, what kind of HP & Torque can a factory D36 handle and can the internals be beefed up with aftermarket gears and so on, and what HP/Torque can some hi-performance D36 internals handle, before someone considers taking out the D36 and putting in a D44 with aftermarket high-performance internal components?
I ask the above question, as once in a while I see someone parting out a 6-speed C4 that has a factory D44 and obtaining a complete D44 with the spider web and then replacing the internals with some heavy-duty bullet proof parts could be a future option.
I ask the above question, as once in a while I see someone parting out a 6-speed C4 that has a factory D44 and obtaining a complete D44 with the spider web and then replacing the internals with some heavy-duty bullet proof parts could be a future option.
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Burning Brakes
Joined: Aug 2023
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From: San Diego
3.07s with an Auto make a huge difference from the 2.59. Its not a super strong rearend, but as long as you dont but street slicks, go drag racing it will last a long time. Once you start putting over 300RWHP to it, it will degrade quickly.
Advanced
Joined: Jan 2021
Posts: 74
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From: NE Ohio
Ah, so 300 RWHP is probably the limit. My 1990 Dark Red C4 Convertible with 24K miles on it, on a Chassis Dyno back on August 9th, recorded 224 HP out of the 245HP TBI 350 L98/TH700R4 with 2.73 ratio D36 rear end. Only modification is the factory mufflers were replaced with 2 1/4" pipes from ANSI out the back, by the 1st owner. So, the 3 catalytics are the mufflers, for now.
I'm just wondering if you can go 350 RWHP or maybe 400 RWHP if you put in some heavy-duty aftermarket components inside the D36 rear end, before replacing the D36 with a stronger/built D44? I have not taken the 1990 C4 to the drag strip (Norwalk Raceway Park is about 35 miles away in Northern Ohio), but I do have new Michelin Pilot Sport All Season P275/40ZR17 tTres with a max speed rating of 186 MPH. At the same time, with a 33 year old car that I just got on June 9th of this year, I don't want to damage the D36 rear end, if 3 passes at the dragstrip in June 2024 would do damage. Granted, I would do more inspection of the rear end and universals and yoke prior to considering a trip to Norwalk to see what the car can record in the 1/4 mile.
I'm just wondering if you can go 350 RWHP or maybe 400 RWHP if you put in some heavy-duty aftermarket components inside the D36 rear end, before replacing the D36 with a stronger/built D44? I have not taken the 1990 C4 to the drag strip (Norwalk Raceway Park is about 35 miles away in Northern Ohio), but I do have new Michelin Pilot Sport All Season P275/40ZR17 tTres with a max speed rating of 186 MPH. At the same time, with a 33 year old car that I just got on June 9th of this year, I don't want to damage the D36 rear end, if 3 passes at the dragstrip in June 2024 would do damage. Granted, I would do more inspection of the rear end and universals and yoke prior to considering a trip to Norwalk to see what the car can record in the 1/4 mile.
Thread Starter
Intermediate
Joined: Nov 2023
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From: Utah
Team Owner
Joined: Sep 2003
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How soon is the LS swap planned?
The one that was offered you if you bought only the actual differential with no rear cover it would fit in a 'tote' and might be shippable using Fastenal 'Blue Line' shipping. With a rear cover I believe it would require a crate or maybe just strapped to a pallet. You might check.
https://www.fastenal.com/fast/blue-lane-freight
The one that was offered you if you bought only the actual differential with no rear cover it would fit in a 'tote' and might be shippable using Fastenal 'Blue Line' shipping. With a rear cover I believe it would require a crate or maybe just strapped to a pallet. You might check.
https://www.fastenal.com/fast/blue-lane-freight
Drifting
Joined: Feb 2017
Posts: 1,274
Likes: 399
From: Tacoma WA
2024 C4 of the Year Finalist - Unmodified
With the horsepower goals you are seeking I would recommend seeking a D44 to swap into the car. There is no way a D36 is going to stand up for long to what you are trying to put down. You need to think about the entire driveline. The auto trans will also need to be upgraded along with the differential.
You might get away with the auto and a D36 if you run tires that will go up in smoke with that kind of horsepower. There will always be a weak link when you are trying to put hp to the ground. It can be mitigated somewhat by only using that hp when already rolling along, but if the drag strip is your goal, Good Luck!
You might get away with the auto and a D36 if you run tires that will go up in smoke with that kind of horsepower. There will always be a weak link when you are trying to put hp to the ground. It can be mitigated somewhat by only using that hp when already rolling along, but if the drag strip is your goal, Good Luck!
Thread Starter
Intermediate
Joined: Nov 2023
Posts: 27
Likes: 1
From: Utah
With the horsepower goals you are seeking I would recommend seeking a D44 to swap into the car. There is no way a D36 is going to stand up for long to what you are trying to put down. You need to think about the entire driveline. The auto trans will also need to be upgraded along with the differential.
You might get away with the auto and a D36 if you run tires that will go up in smoke with that kind of horsepower. There will always be a weak link when you are trying to put hp to the ground. It can be mitigated somewhat by only using that hp when already rolling along, but if the drag strip is your goal, Good Luck!
You might get away with the auto and a D36 if you run tires that will go up in smoke with that kind of horsepower. There will always be a weak link when you are trying to put hp to the ground. It can be mitigated somewhat by only using that hp when already rolling along, but if the drag strip is your goal, Good Luck!
Last edited by XanBarclay07; Dec 19, 2023 at 01:08 PM.
Thread Starter
Intermediate
Joined: Nov 2023
Posts: 27
Likes: 1
From: Utah
How soon is the LS swap planned?
The one that was offered you if you bought only the actual differential with no rear cover it would fit in a 'tote' and might be shippable using Fastenal 'Blue Line' shipping. With a rear cover I believe it would require a crate or maybe just strapped to a pallet. You might check.
https://www.fastenal.com/fast/blue-lane-freight
The one that was offered you if you bought only the actual differential with no rear cover it would fit in a 'tote' and might be shippable using Fastenal 'Blue Line' shipping. With a rear cover I believe it would require a crate or maybe just strapped to a pallet. You might check.
https://www.fastenal.com/fast/blue-lane-freight
Drifting
Joined: Feb 2017
Posts: 1,274
Likes: 399
From: Tacoma WA
2024 C4 of the Year Finalist - Unmodified
Just for clarification the 3:07 that I have is only the pumpkin.
Common failures with the D36 include cracked cases, destroyed ring and pinions, and sometimes more catastrophic failures. However this is usually from shock applied from trying to hook up at drag racing. Since you are mostly thinking of using it on a road course you might get away with it.
If you are thinking of specific courses it would be helpful for you to choose a ratio that would allow you to hold that auto in specific gears that allow you to run in the ideal RPM range throughout the course. I am a great many years from the time I spent on courses back in Connecticut but auto-x cars that compete locally do well with D36s and 3:54 gears. Talk to local people and see what they tell you about RPM ranges on the tracks you are considering.
Common failures with the D36 include cracked cases, destroyed ring and pinions, and sometimes more catastrophic failures. However this is usually from shock applied from trying to hook up at drag racing. Since you are mostly thinking of using it on a road course you might get away with it.
If you are thinking of specific courses it would be helpful for you to choose a ratio that would allow you to hold that auto in specific gears that allow you to run in the ideal RPM range throughout the course. I am a great many years from the time I spent on courses back in Connecticut but auto-x cars that compete locally do well with D36s and 3:54 gears. Talk to local people and see what they tell you about RPM ranges on the tracks you are considering.