What to do about the IRS.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
What to do about the IRS.
Ok, well I just thought I was through throwing money into the money pit. I guess I was wrong. I finally got everyhting back together, engine, front suspension, 5-spd... So, I took it to the alignment shop today, and much to my dismay, I discovered the half-shafts have excessive play in them. So it seems that I will have to be tearing into the 3rd member soon. I just wanted to get some suggestions on what direction I should take in beefing things up a bit without spending a lot of dough. (So all of the fans of Tom's out there can just forget about it, I don't have an extra $5000 to spend on my rear end.) What I am looking to do here is just to make small improvments here and there, and I want to try and maintain a somewhat factory appearance. My setup should be producing around 500hp and 550ft/lbs at the flywheel, and the car will be street driven, with maybe just an occasional pass at the strip. I have about only have about $1000 to spend, so I need to choose wisely here... Give me your thoughts 
Last edited by LS-Five; Aug 15, 2005 at 04:37 PM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Your problem is not the 3rd member. If it is properly setup it will be able to handle your combo as long as you are not using slicks. You might want to put in a set of HD yokes and solid ujoints will help also. The problem is not so much HP as it is traction. If you are running street tires you should not have a problem.
Melting Slicks
Joined: Dec 2000
Posts: 2,041
Likes: 0
From: Wichita, KS
You've set a pretty tough budget to keep with the amount of power that you've got.
The weakest link is the U-joints. The general consenses is to use Spicer joints. They do not have a lube fitting. I prefer to install the joints so that the force is acting in compression on the grease fitting and use a greasable U-joint. I try to lube them every 2 months in the summer time no matter how many or few miles that I've driven.
Install bearing caps to replace the U-bolts if that is the type of bolt that you have holding the U-joints in place. Moroso and others have them. Check the torque on the caps regularly.
Paint a stripe on your half shafts so that you have a referance point in case they twist. Maybe you can catch it before it's too late. I've only heard of this happening on cars with slicks.
Have your rear end rebuilt by someone that knows Corvette's. Have the outer axle splines checked at the same time.
Enjoy!
The weakest link is the U-joints. The general consenses is to use Spicer joints. They do not have a lube fitting. I prefer to install the joints so that the force is acting in compression on the grease fitting and use a greasable U-joint. I try to lube them every 2 months in the summer time no matter how many or few miles that I've driven.
Install bearing caps to replace the U-bolts if that is the type of bolt that you have holding the U-joints in place. Moroso and others have them. Check the torque on the caps regularly.
Paint a stripe on your half shafts so that you have a referance point in case they twist. Maybe you can catch it before it's too late. I've only heard of this happening on cars with slicks.
Have your rear end rebuilt by someone that knows Corvette's. Have the outer axle splines checked at the same time.
Enjoy!
Melting Slicks
Joined: Nov 2003
Posts: 2,362
Likes: 1
From: San Antonio TX
I have to agree on the Spicer U Joints. You might even want to take a look at DragVette as they have new Half Shafts with the Spicer U Joints for a very good price. They also offer other solutions that may help as well. You can give them a shout and they will be more than happy to talk to you about it. 
Drifting
Joined: Nov 2001
Posts: 1,469
Likes: 6
From: 68 427 4.11s Roadster
If your doing the work yourself then do the U-joints and the bearings. I would also toss the old spindles and get new ones.
Maybe check the bushings back there. A spring is also in the budget, if yours isn't plastic.
If your having it done then just do the bearings and maybe the U-joints.
The spicers now have plastic seals so van steel sells a different joint because of this. Something to consider about spicers.
I have a question on the greaseable U-joints. Does the grease come out of all 4 points or just one?
I bought the non greasers for several reasons but am wondering how long the grease continues reaching all 4 caps.
Maybe check the bushings back there. A spring is also in the budget, if yours isn't plastic.
If your having it done then just do the bearings and maybe the U-joints.
The spicers now have plastic seals so van steel sells a different joint because of this. Something to consider about spicers.
I have a question on the greaseable U-joints. Does the grease come out of all 4 points or just one?
I bought the non greasers for several reasons but am wondering how long the grease continues reaching all 4 caps.
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Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
For $1000, I'd just get a tight composite rear spring to prevent damage from excessive squatting... (360 lbs/ inch or stiffer)..
That should be about $299... which leave $700 for other mods.. A bullet proof rear end will cost you about $4500.... (Tom's 12-bolt)
That should be about $299... which leave $700 for other mods.. A bullet proof rear end will cost you about $4500.... (Tom's 12-bolt)
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
I'll chime in
Things I have done to keep the IRS alive. This is the stock rear end with 150,000 miles. Over 100 passes at the drag strip with a mix of slicks and street tires. 60' of 1.67 seconds.
1) Spicer Solid HD u-joints
2) Guldstrand solid diff mounts
3) Royal Purple MAX Gear 85-140W oil
4) Dragvette Half Shaft Loops
5) Dragvette Suspension Kit
The key to keeping it alive is not shocking it (read: Manual).
Things I have done to keep the IRS alive. This is the stock rear end with 150,000 miles. Over 100 passes at the drag strip with a mix of slicks and street tires. 60' of 1.67 seconds.
1) Spicer Solid HD u-joints
2) Guldstrand solid diff mounts
3) Royal Purple MAX Gear 85-140W oil
4) Dragvette Half Shaft Loops
5) Dragvette Suspension Kit
The key to keeping it alive is not shocking it (read: Manual).
Race Director
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From: Corsicana, Tx
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For sure the solid Spicers. Then I'd look into better outer stub shafts. I've yet to break an inner one, but I've killed a few outers. But since yours are worn, you have to replace them.
At this point we've put a hurt on the 1K limit...but we do need to do something with geometry. If you can't swing the VB Smart Struts kit, then at least make a spacer or use the one that Drag Vette sells to lower inner mounting point of strut rods. You need to make it where it doesn't go through wild camber changes and you can do that with a little fabrication or a 1" or so spacer block.
Also get the aluminum mount kit for rear crossmember,,it will help.
We've blown the budget, but later on you can get into the inner stuff.
JIM
At this point we've put a hurt on the 1K limit...but we do need to do something with geometry. If you can't swing the VB Smart Struts kit, then at least make a spacer or use the one that Drag Vette sells to lower inner mounting point of strut rods. You need to make it where it doesn't go through wild camber changes and you can do that with a little fabrication or a 1" or so spacer block.
Also get the aluminum mount kit for rear crossmember,,it will help.
We've blown the budget, but later on you can get into the inner stuff.
JIM
Burning Brakes
Joined: Jul 2005
Posts: 866
Likes: 1
From: Northeast Ohio
For the money I went with these.
http://cgi.ebay.com/ebaymotors/Corve...QQcmdZViewItem
and 2 of these.
http://cgi.ebay.com/ebaymotors/63-79...QQcmdZViewItem
http://cgi.ebay.com/ebaymotors/Corve...QQcmdZViewItem
and 2 of these.
http://cgi.ebay.com/ebaymotors/63-79...QQcmdZViewItem
Last edited by dboz; Aug 15, 2005 at 11:14 PM.
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Ok, I'll provide a little more info. I have the VBP smart struts, new timken bearings, new 9 leaf steel spring, and I also replaced the spindle on the passenger side last year. I think the spicer u-joints are a good place to start. I was also considering the HD caps to replace my u-bolts. I don't ever plan on running slicks, but I may not be able to resist the temptation to borrow a set of drag radials to bolt on just to make a few passes for bragging rights. 
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Originally Posted by Techno
And get sidepipes.
This gets that mess away from the rearend work and also away from the plastic spring.
Just a consideration
This gets that mess away from the rearend work and also away from the plastic spring.
Just a consideration
Whoa there. That would eat up my $1000 bucks real quick. I would have to go out and start selling sex on the street corner to make up the rest. On second thought, that might just put me deeper in debt!
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Originally Posted by dboz
For the money I went with these.
http://cgi.ebay.com/ebaymotors/Corve...QQcmdZViewItem
and 2 of these.
http://cgi.ebay.com/ebaymotors/63-79...QQcmdZViewItem
http://cgi.ebay.com/ebaymotors/Corve...QQcmdZViewItem
and 2 of these.
http://cgi.ebay.com/ebaymotors/63-79...QQcmdZViewItem
Hmmm. Have you got them installed yet? I must admit that is very tempting. Any idea what brand of u-joint they are using? Anyone else out there had any experiences with these guys, good or bad?
Thread Starter
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Originally Posted by VETDRMS
I'll chime in
Things I have done to keep the IRS alive. This is the stock rear end with 150,000 miles. Over 100 passes at the drag strip with a mix of slicks and street tires. 60' of 1.67 seconds.
1) Spicer Solid HD u-joints
2) Guldstrand solid diff mounts
3) Royal Purple MAX Gear 85-140W oil
4) Dragvette Half Shaft Loops
5) Dragvette Suspension Kit
The key to keeping it alive is not shocking it (read: Manual).
Things I have done to keep the IRS alive. This is the stock rear end with 150,000 miles. Over 100 passes at the drag strip with a mix of slicks and street tires. 60' of 1.67 seconds.
1) Spicer Solid HD u-joints
2) Guldstrand solid diff mounts
3) Royal Purple MAX Gear 85-140W oil
4) Dragvette Half Shaft Loops
5) Dragvette Suspension Kit
The key to keeping it alive is not shocking it (read: Manual).
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
LS-Five:
1) Spicer Solid HD u-joints
-6 joints at $20 per joint - $120 (I think they have gone up in price)
2) Guldstrand solid diff mounts
- I bought these from redvetrcr I believe for $50
3) Royal Purple MAX Gear 85-140W oil
- 2 bottles at $10 per bottle - $20 (extra for leaks)
4) Dragvette Half Shaft Loops
- $119
5) Dragvette Suspension Kit
- $250
Total: $559
You don't need the loops to keep the rear end alive, but if a half shaft should come off it will save you $$$ as your battery box will still be in one piece. Also, our cars need them per NHRA rules if running faster than 13.00.
1) Spicer Solid HD u-joints
-6 joints at $20 per joint - $120 (I think they have gone up in price)
2) Guldstrand solid diff mounts
- I bought these from redvetrcr I believe for $50
3) Royal Purple MAX Gear 85-140W oil
- 2 bottles at $10 per bottle - $20 (extra for leaks)
4) Dragvette Half Shaft Loops
- $119
5) Dragvette Suspension Kit
- $250
Total: $559
You don't need the loops to keep the rear end alive, but if a half shaft should come off it will save you $$$ as your battery box will still be in one piece. Also, our cars need them per NHRA rules if running faster than 13.00.
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Originally Posted by Techno
And get sidepipes.
This gets that mess away from the rearend work and also away from the plastic spring.
This gets that mess away from the rearend work and also away from the plastic spring.
Heat is the only thing that would cause wear on a composite spring.. I love my sidepipes.. Makes it a lot easier to work on the rear end and other components...
Burning Brakes
Joined: Jul 2005
Posts: 866
Likes: 1
From: Northeast Ohio
Originally Posted by LS-Five
Hmmm. Have you got them installed yet? I must admit that is very tempting. Any idea what brand of u-joint they are using? Anyone else out there had any experiences with these guys, good or bad?
body is still off car. so they are not installed, and no engine for months so they are not tested either. but i have about the same power as you do. the parts seem high quality. you won't find any cheaper and just call them and i am sure they can answer your technical questions. or just email them. they can tell you what kind of power they will hold.