Dana 36 Gear Upgrade

[vms4evr]

Doutdoor and Corvette-Pilot,
If you have never done a gear swap before I would strongly recommend you do not do it. And make sure the shop you go to has done it many times before, specifically on Vettes. The guy that did my gears has worked on C4s since the 84 came out. He did the work right on my car so the rear didn't need to be taken to a shop. Even he said putting those thick gears in the Dana 36 was a PITA. He spent 4hrs just mucking with gears to get them exactly the way he wanted them. He's also very picky. He ended up loosing on the labor because he spent so much time on the gear alignment. So I made out on the deal. It cost me about $1,000 all said and done. He said it should have been more like $1,200. He was really annoyed that I didn't just go with a Dana 44 setup and told me no hardcore drag racing. If the car will go to the strip a lot the Dana 36 won't take it.
As for the gears themselves I looked at Randy's and the Yukon gears they sell. I also looked at Richmond, of course, and Precision Gear, Motive and Strange. I went with Strange (US Gear) just because I have experience with their parts in the past. The gear quality is excellent. There is some whine with the gears. But it is not constant. Coasting at certain speeds I hear it if the radio is off with the factory exhaust. Sounds like your driving a stick that is coasting down in a lower gear. Not bad or annoying to me. But I doubt it will be as quiet as the factory 2.59 gears. I don't mind that sound knowing how much I like the gears
Graham

 

[Corvette-Pilot]

Doutdoor and Corvette-Pilot,
If you have never done a gear swap before I would strongly recommend you do not do it.

I had no intention of trying the internals myself !!:nono

I was more curious about how much it takes just to get the pumpkin out so I can take it to someone. But now that spring is near I might as well give them the whole car.

Would a change over to a Dana 44 be anything more than drop out one and reinstall the other?? Or are there differences in driveshaft and axle lenght issues? Maybe the best bet is just to find a used 44 rear end

 

[Doutdoor]

I talked to a shop today and they told me it's not too complicated to remove the rear end. You will need torx bits (not sure I spelled that right) for most of the metric fasteners. I'd love to be able to save the extra money and R&R the rear end assembly myself, but I think it's probably money well spent to have a knowledgable professional do all of the work. Esp. with also having to install the correct rear tranny gears so everything works properly.

The shop I talked to also said the Dana 36 is fine for anything except extreme driving/racing. They also said the Dana 44's are hard to come by. I wasn't able to find out anything on how involved a 36 - 44 swap would be.

Dave

 

[mauivette]

rear end swap

OK, I'm sold. I am going to do the 3:73 rear end gears. Just a couple questions though, since I have an auto I have the Dana 36 case. Should I buy a Dana 44 case and just have the new gears installed in that. That way I have the old rear end should I ever wish to reinstall it later. Also, I have found a couple good and REASONABLE sources to the rear end gear rebuilds but I haven't found a good source for a Dana 44 case. Anyone know a reasonable source. I have found a very good mechanic locally who is reasonably priced, and you thought they didn't exist, huh.
He will install the gears and bearings for me for a fraction of what an assembled unit costs. Plus, living on a tropical island I suppose that all this will have to be shipped here by boat and that takes a lot of time. Weeks and weeks. Sometimes it is hard to wait but air shipping can be expensive on heavy parts. TIPI"s seem to have good prices on rear end kits. Both 36 and 44. Any thoughts are appreciated.

 

[Rich96c4ce]

You need a D44 driveshaft, drive shaft beam, and D44 half-shafts besides the D44 differential housing and cover, to switch from a D36. The D44 is longer and wider. Check it out.

 

[mauivette]

Thanks for the heads up on that. Sounds like a lot of money unless you are going to race. Any source for a Dana 36 "pumpkin" would be appreciated. If I lived on the mainland I would just go to a junkyard, but things are hard to comeby here in the islands. Plus there is that shipping thing again.

Once more, thanks for all the knowledge and experience from you all on the mainland.

Skip

 

[vms4evr]

I yanked the whole pumpkin because I started having problems about 18mo after the original gear swap. I did an exhange for a complete rebuilt pumpkin with new 3.54 gears, new bearings, posi clutch packs and side yolks. I have over 1,000 miles on it now and it is quiet and works like a charm. I got it from Ikerds and am very happy with those folks. www.ikerds.com

As for your shipping costs, well that's your problem. That's what happens when you live on an awesome island in the middle of the ocean

Graham

 

[Rich96c4ce]

FYI - D44 conversion for sale on ebay

http://cgi.aol.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2441732022&category=33731

 

[Rich96c4ce]

I yanked the whole pumpkin because I started having problems about 18mo after the original gear swap. I did an exhange for a complete rebuilt pumpkin with new 3.54 gears, new bearings, posi clutch packs and side yolks. I have over 1,000 miles on it now and it is quiet and works like a charm. I got it from Ikerds and am very happy with those folks. www.ikerds.com

As for your shipping costs, well that's your problem. That's what happens when you live on an awesome island in the middle of the ocean

Graham

Ikerds has a really nice heavy duty D36 cover that supports the differential bearing caps. I just got one for my D36 rebuild to a 3.75. The pumpkin and cover need to go to a machine shop so that the caps can be skim milled so that the cover's support blocks can just push on them when the cover is installed.

 

[mauivette]

Thanks for all the good info.

As per shipping, it isn't so much the expense as it is the waiting.
Thanks for all your experience and expertice. I appreciate it immensely.

Skip

 

[fastglass95]

What's wrong with a DANA 36?

Just for your information,

I had my original Dana 36, 2:59 geared rear-end up-graded by a local speed shop to the "thick" ring geared 3:73 set. This eliminates using excess shims when going from 2:59 to 3:73.

Anyway, 4 years , and 20,000 miles with no problems. Use good synthetic rear end lube such as "Red Line- heavywieght" (it's blue).

This car has been autocrossed for 3 years now with two drivers at each event running Kumho autocross tires. And we run hard!

I belive regular drag racing with wrinkle wall tires would be tough on any rear-end assembly.

Automatic transmissions take up much of the shock of heavy loads that 6 speeds can put out with 3,000 rpm launches.

Go for the 3:73's in the Dana 36.

Just my opinion,

Tom

 

[Rich96c4ce]

Sounds good to me.

I hope mine does as well. Its going in this winter.

 

[ratorto]

I pu the 3:73 Richmond gears in my 87 replacing the 2:55s.
Best mod ever for the cost (parts $300).
Low end performance is much improved with no noticable side effects.
It now squeals between the gears....what a nice sound!

 

[keefyboy]

Stupid n00b question time:

How hard is it to DIY the ring and pinion?

I'm not talking getting the carrier out of the car - I can do that easy enough...;help (yeah, who do I think I am, Killebrew?)

How hard is it to pull and replace the clutches in the differential and swap the ring and pinion, and get it all adjusted properly? Or are there any adjustments in the carrier itself? I have airtools and such, and I *hate* the 2.59. WhoTF orders a high-performance car with an ECONO-GEAR?!? *Especially* when the 3.0-something was only FIFTY BUCKS MORE?!? (end rant!)
-keith

 

[mauivette]

Dana 36 Rebuild

Anyone out there who's vast experience I can draw on. I bought a new used "pumpkin". I got the pinion nut off (Air impact wrench) but can't seem to get the two snap rings off that hold the yoke shafts. I have now bought 2 different kinds of snap ring pliers from NAPA. They are loose but when I get them expanded they always seem to slip off the pliers. Any tricks or do I just keep on tryin.

I'm getting pretty anxious to install the 3.73 gears and try them.

Mahalo

Skip

 

[Rich96c4ce]

I had the same problem; just gotta keep trying, but with 45 or 90 degree tips. I got the HD one that Lisle makes. Got it at PepBoys. Worked great.

 

[Hib Halverson]

There's no question that given enough tire and not too much torque output, upgrading the D36 axle from 2.59 to 3.07, 3.55 or 3.73 can make a significant improvment in acceleration.

considering D36 axles go with automatics having a 3.06 low gear, I wouldn't go any more than 3.54 unless you're going to start using sticky tires on the back. The 3.73s add so much to first gear that many cars will be spinning the tires so much to make the advantage of the short gears, much less in a practical sense.

One thing to watch is the amount of torque you put through the D36, especially if you go to sticky tires. That axle is pretty iffy once you go past 350 lbs/ft. torque and tires like drag radials or racing slicks make the reliability issue even more critical.

Caution: someone posted

Anyway, 4 years , and 20,000 miles with no problems. Use good synthetic rear end lube such as "Red Line- heavywieght" (it's blue).

Red Line Heavy Shockproof is red not blue. This is an important issue because Red Line Light Shockproof is blue but is not recommended for street use in rear axles. The Red Line Shockproof series of gear lubricants are an excellenct choice for gear sysetms subjected to extreme duty, but for street use, the Heavy, not the Light, is the way to go.