Product Review - Rennbay ball joint kit
08-14-2003, 12:18 PM
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Product Review - Rennbay ball joint kit
I've installed the Rennbay ball joint kit on one of my control arms and I thought I'd do a product review. Overall, I'm really pleased with the quality of the kit and results. The ball joint is now very tight, smooth and quiet.
The installation was relatively easy except for the removal of the Porsche style retaining ring at the bottom. The Rennbay supplied snap ring is so much more easily installed and removed! I actually took the ball joint apart again after about a week of driving for inspection - it was still tight and smooth.
The Rennbay supplied boot is different than the Porsche version. There are no retaining rings used with the Rennbay boot. The Porsche version has a retaining ring at the top and an awkward spiral retaining ring at the bottom - I tore the Porsche boot trying to take that spiral retaining ring off. The Rennbay boot is just slid on and compressed in place when you attach the ball joint to the spindle. It seems to fit very tightly and the bottom conforms around the lip on the control arm, but I did notice a small amount of grease seepage from the bottom of the boot after about a week.
Here is a comparison of the Porsche parts(top row) with the Rennbay kit(bottom row). The old top bushing had disintegrated and only these pieces were left - but my control arm had over 342,000 Kms(212,000 Miles) on it and had never been rebuilt before!
The Rennbay o-ring seal is slightly thinner than the Porsche o-ring seal(not shown) but otherwise the same diameter.
I elected not to install the zerk fitting kit that allows you to regrease the joint. The ball joint is so easy to disassemble, especially with the Rennbay snap rings, that I will just take it apart, clean it, inspect it and regrease it instead.
Great product!
Regards,
Jim
The installation was relatively easy except for the removal of the Porsche style retaining ring at the bottom. The Rennbay supplied snap ring is so much more easily installed and removed! I actually took the ball joint apart again after about a week of driving for inspection - it was still tight and smooth.
The Rennbay supplied boot is different than the Porsche version. There are no retaining rings used with the Rennbay boot. The Porsche version has a retaining ring at the top and an awkward spiral retaining ring at the bottom - I tore the Porsche boot trying to take that spiral retaining ring off. The Rennbay boot is just slid on and compressed in place when you attach the ball joint to the spindle. It seems to fit very tightly and the bottom conforms around the lip on the control arm, but I did notice a small amount of grease seepage from the bottom of the boot after about a week.
Here is a comparison of the Porsche parts(top row) with the Rennbay kit(bottom row). The old top bushing had disintegrated and only these pieces were left - but my control arm had over 342,000 Kms(212,000 Miles) on it and had never been rebuilt before!
The Rennbay o-ring seal is slightly thinner than the Porsche o-ring seal(not shown) but otherwise the same diameter.
I elected not to install the zerk fitting kit that allows you to regrease the joint. The ball joint is so easy to disassemble, especially with the Rennbay snap rings, that I will just take it apart, clean it, inspect it and regrease it instead.
Great product!
Regards,
Jim
Last edited by jpapanas; 03-22-2005 at 10:09 PM.
08-14-2003, 12:26 PM
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Great. I bought a kit when Travis fist started selling them. I'm saving it for a boring winter day. It should be good for my 175,000 mile joints.
08-20-2003, 10:26 PM
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Can these kits replace the bad ball joint on our later 944's? I thought to rebuild our ball joints, the new joints had to be pressed into the control arm...as in, you need special tools?
I went to a different mechanic (finally) who said my right ball joint is shot. I thought my only sensible option was rebuilt control arm for $199 plus core charge...? Are these kits a do-it-on-the -car type of fix??
I went to a different mechanic (finally) who said my right ball joint is shot. I thought my only sensible option was rebuilt control arm for $199 plus core charge...? Are these kits a do-it-on-the -car type of fix??
08-20-2003, 10:33 PM
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These are for the late (post 85) cars. This has been a recent development over the last year or so. The Kit on Rennbay has received a lot of good reviews.
I bought the SSI kit, which is a little beefier (and thus more expensive). I think that website is www.ssiauto.com. It comes with brass bushings and new balljoints....Danno has a good write up on these on his site as well.
Tifo
I bought the SSI kit, which is a little beefier (and thus more expensive). I think that website is www.ssiauto.com. It comes with brass bushings and new balljoints....Danno has a good write up on these on his site as well.
Tifo
08-20-2003, 10:34 PM
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Andy,
This isn't really something that can be done with the arm on the car...I dont really see how you could do it without pulling the arm...
All you need is a large Vice or a large C-clamp, big socket, small socket and a flat screwdriver or 2...Check out the tutorial on the rennbay site. http://www.rennbay.com/balljointtutorial.html
It's really not hard at all...I'll be in school in New Brunswick starting August 31st. We could have a Balljoint party and get the gang together and do em if you like. Or I could just come by...
Is this your daily driver?
You don't NEED an alignment persay if you mark everything up, but I would still recommend it. I had all the marks lined up when I put mine back together, but it apparently wasn't exact enough because the car pulled to one side.
I'm really not sure why people say that late A-arms are not rebuildable...I think it was just the lack of availability of parts.
This isn't really something that can be done with the arm on the car...I dont really see how you could do it without pulling the arm...
All you need is a large Vice or a large C-clamp, big socket, small socket and a flat screwdriver or 2...Check out the tutorial on the rennbay site. http://www.rennbay.com/balljointtutorial.html
It's really not hard at all...I'll be in school in New Brunswick starting August 31st. We could have a Balljoint party and get the gang together and do em if you like. Or I could just come by...
Is this your daily driver?You don't NEED an alignment persay if you mark everything up, but I would still recommend it. I had all the marks lined up when I put mine back together, but it apparently wasn't exact enough because the car pulled to one side.
I'm really not sure why people say that late A-arms are not rebuildable...I think it was just the lack of availability of parts.
08-20-2003, 11:41 PM
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Adrial-
I have no vice, or c-clamps! I assume you would have to put the car on blocks to remove the arm, right? Your tutorial is great! But seems pretty complicated to my ignorant self!
How long would something like this take someone...like you or your brother... to do??
I have no vice, or c-clamps! I assume you would have to put the car on blocks to remove the arm, right? Your tutorial is great! But seems pretty complicated to my ignorant self!
How long would something like this take someone...like you or your brother... to do??
08-20-2003, 11:57 PM
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Nordschleife Master
I could bring the tools necesary to do it at your house if you like.
The tutorial may seem intimidating but I think once you get into it you'll be thinking... "oh...he wrote all that for THIS??"
Yup, the car should go up on jack stands to remove the a-arm. You could just hold it up with jacks, but thats just asking for trouble.
I'm gonna guess 4 or so hours from start to finish...
Take this as an opportunity to get under the car and save some $$.
If you're gonna be doing Koni's...this would be the time to do it as the car will already be needing an alignment...
The tutorial may seem intimidating but I think once you get into it you'll be thinking... "oh...he wrote all that for THIS??"
Yup, the car should go up on jack stands to remove the a-arm. You could just hold it up with jacks, but thats just asking for trouble.
I'm gonna guess 4 or so hours from start to finish...
Take this as an opportunity to get under the car and save some $$.
If you're gonna be doing Koni's...this would be the time to do it as the car will already be needing an alignment...
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08-21-2003, 12:11 AM
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Jim,
Thank you for the great review. I am so glad you like the kit and that the installation went well.
When designing the kits I fought back and forth with the style of boot that I wanted to use. The stock type boots seal better around the lip and top but they are also almost always destroyed when removing the arm from the spindle. The polyurethane boots will not rip when you use a fork bar to remove the arm but they dont seal as well at the base. After much thought I went with the tougher polyurethane boots which are the ones you see in the kits now. All in all I think it was a wise choice.
I have had a few requests for replacement springs to go under the ball joints. After extensive searching I could not find an exact match so I went ahead and had some custom wound/ground. I put them up on the web page with the ball joint kits if anyone is interested in them.
Thank you for the great review. I am so glad you like the kit and that the installation went well.
When designing the kits I fought back and forth with the style of boot that I wanted to use. The stock type boots seal better around the lip and top but they are also almost always destroyed when removing the arm from the spindle. The polyurethane boots will not rip when you use a fork bar to remove the arm but they dont seal as well at the base. After much thought I went with the tougher polyurethane boots which are the ones you see in the kits now. All in all I think it was a wise choice.
I have had a few requests for replacement springs to go under the ball joints. After extensive searching I could not find an exact match so I went ahead and had some custom wound/ground. I put them up on the web page with the ball joint kits if anyone is interested in them.
08-21-2003, 02:59 AM
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Adrial,
I had a similar problem with the alignment afterwards even though I left the rear caster block attached to the control arm - a very, very, slight pull to one side and the steering wheel is now actually very slightly off center as well.
As you can see in the comparison picture, most of the wear occurs in the top bushing, so I suspect that the alignment changes slightly over time as the top bushing wears down. Since the new top bushing is thicker, compared to the worn down bushing, the alignment is bound to change slightly at the ball joint, especially if you only do one side as I did.
I had a rebuilt control arm installed on the other side a few years ago before a drivers ed event for about $350USD including alignment. I think its still ok, that's why I didn't replace that side yet - but look at that price compared to the Rennbay kit!
Has anyone used www.944racing.com rebuilt control arms - they are only $99(+$75core). I think those include new front pivot bushings as well as rebuilt ball joints with new ball joint pins and bushings. You can barely rebuild it yourself for that price: (1/2 rennbay kit($32.50) + ball joint pin($14.99) + front pivot bushings($50.89) - so this seems like a good deal if you don't want to rebuild it yourself.
Regards,
Jim
You don't NEED an alignment persay if you mark everything up, but I would still recommend it. I had all the marks lined up when I put mine back together, but it apparently wasn't exact enough because the car pulled to one side.
As you can see in the comparison picture, most of the wear occurs in the top bushing, so I suspect that the alignment changes slightly over time as the top bushing wears down. Since the new top bushing is thicker, compared to the worn down bushing, the alignment is bound to change slightly at the ball joint, especially if you only do one side as I did.
I had a rebuilt control arm installed on the other side a few years ago before a drivers ed event for about $350USD including alignment. I think its still ok, that's why I didn't replace that side yet - but look at that price compared to the Rennbay kit!
Has anyone used www.944racing.com rebuilt control arms - they are only $99(+$75core). I think those include new front pivot bushings as well as rebuilt ball joints with new ball joint pins and bushings. You can barely rebuild it yourself for that price: (1/2 rennbay kit($32.50) + ball joint pin($14.99) + front pivot bushings($50.89) - so this seems like a good deal if you don't want to rebuild it yourself.
Regards,
Jim
08-21-2003, 03:51 AM
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We have some new chrome-moly arms with a replacable ball-joint.Actually it is a teflon lined heim joint that will never need replacing.The rubber bushings get replaced with Delrin bushings.The arms are just as nice as anything else being offered but alot cheaper. I will post some pictures tomorrow night. Price is going to be $899 for the set but if we can get a group buy going.......we can bring the price down some more;^)
08-21-2003, 09:59 AM
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Hey, $99 for a rebuilt arm seems like the way to go!? Thanks for the link!
Adrial- I plan on having the Koni's put in...maybe 2 rebuilt arms, plus a set of Koni Yellows would do the trick! Doesn't sound like a driveway project though, does it?
Adrial- I plan on having the Koni's put in...maybe 2 rebuilt arms, plus a set of Koni Yellows would do the trick! Doesn't sound like a driveway project though, does it?
08-21-2003, 12:04 PM
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Originally posted by TurboTim
We have some new chrome-moly arms with a replacable ball-joint.Actually it is a teflon lined heim joint that will never need replacing.The rubber bushings get replaced with Delrin bushings.The arms are just as nice as anything else being offered but alot cheaper. I will post some pictures tomorrow night. Price is going to be $899 for the set but if we can get a group buy going.......we can bring the price down some more;^)
We have some new chrome-moly arms with a replacable ball-joint.Actually it is a teflon lined heim joint that will never need replacing.The rubber bushings get replaced with Delrin bushings.The arms are just as nice as anything else being offered but alot cheaper. I will post some pictures tomorrow night. Price is going to be $899 for the set but if we can get a group buy going.......we can bring the price down some more;^)
08-21-2003, 12:20 PM
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Nordschleife Master
Originally posted by AndyK
Hey, $99 for a rebuilt arm seems like the way to go!? Thanks for the link!
Adrial- I plan on having the Koni's put in...maybe 2 rebuilt arms, plus a set of Koni Yellows would do the trick! Doesn't sound like a driveway project though, does it?
Hey, $99 for a rebuilt arm seems like the way to go!? Thanks for the link!
Adrial- I plan on having the Koni's put in...maybe 2 rebuilt arms, plus a set of Koni Yellows would do the trick! Doesn't sound like a driveway project though, does it?
I expect it'd be done in a day no problem..
Would your koni's be the take out old, bolt in new? Or take out old, saw them in half, assemble strut, bolt in new?
So you dont have a garage to work in?
08-21-2003, 02:21 PM
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If we were doing it in the garage (small, but doable), I would order the pre-made units from Paragon. They would be about $600. Eurotire on Rt 46 here in NJ offered to order the struts, install, and align, all for $835. Seems like a great deal. Problem is, there is still the ball joint.
Maybe it pays to do the control arm replacement and Koni upgrade at Eurotire? I will be back to work on Monday, and wont have much time to have a suspension "party" here on the weekend.
I also have my mechanic calling me, saying he is free for me to bring the car in now that he has caught up.
Decisions, decisions!?
Maybe it pays to do the control arm replacement and Koni upgrade at Eurotire? I will be back to work on Monday, and wont have much time to have a suspension "party" here on the weekend.
I also have my mechanic calling me, saying he is free for me to bring the car in now that he has caught up.
Decisions, decisions!?
08-22-2003, 02:29 PM
#15
Three Wheelin'
Tim,
Do you have the pictures, yet? I'm very interested to see your new product. I'm sure you'll have no problem finding buyers.
Andy,
$835 for labor, or $835 for everything? Do they know what's involved? I'm just curious, because that seems too good to be true. If they're going to do that much for that cheap, I doubt that it would cost more than $100 to have them do the ball joint while they're in there.
-Jon
Do you have the pictures, yet? I'm very interested to see your new product. I'm sure you'll have no problem finding buyers.
Andy,
$835 for labor, or $835 for everything? Do they know what's involved? I'm just curious, because that seems too good to be true. If they're going to do that much for that cheap, I doubt that it would cost more than $100 to have them do the ball joint while they're in there.
-Jon