SLC ball joints?

Howard Jones

Member
GT40s Supporter
#1
I took my suspension apart and am looking to install new ball joints. The only markings on them are "OEM" and the number 40407 on different areas on the piece. Lots of googleing and so far no joy. I think I found this once before but it has slipped my mind. Can anyone point me to a part number for a Moog or other high quality ball joint to suit.
 

Howard Jones

Member
GT40s Supporter
#9
I have received a set of new ball joints from Summit Racing, They seam to be a bit stiff but after I cleaned them out and re greased with new grease they seamed to free up quite a bit. I really like red line products so I use them. I am sure other manufactures products work well also. Just stay away from the 3 dollar stuff. Look for a temp range of at least 400F. This stuff I use is good up to 500F. Why? the heat generated by the rotors is very high and the ball joint is very close to that heat source. When I removed the original ball joints the rubber boots were hard and cracked from the heat and the grease inside looked over heated to me as it was dry and seamed to have been overheated. I will check these after every track weekend from now on.

On to the fitting, The K6136 is about 3/16s taller than the OEM piece. I will make a spacer to fit between the mounting plate and the A arm. This should place it in the original position. I also ordered a 7 degree reamer to clean up the stud hole in the plate on the bottom of the upright. The original placement left about 3/32s inch of threads in the hole. I would like to have the entire stud bearing surface in the hole with maybe a single thread left to be pulled into place as the bolt is tightened. More on this as I final fit the ball joints in the assembly.

I have contacted RCR about the availability of the spherical bearing retrofit piece and would be interested in at least having a look to see if I want to re fit them into my car. More on that if I get any info from RCR.

If anybody has pictures of these please post them.

https://www.redlineoil.com/cv-2-grease

https://www.summitracing.com/parts/mog-k6136
 
Last edited:
#10
There is another possibility for ball joints. I've not had one in my hand, but they appear well well made, are intended for racing, and are from a respected chassis manufacturer.

This is the HOWE 22301 and HOWE 22301S. It is cross referenced with K6136. These are about $70 from the normal online sources, rebuild-able and available with different length studs (Standard, and +0.1" increments to 0.5").

The boots are part numbers 22399 $5 or 22399V $10 (Viton).
 

Will Campbell

Member
GT40s Supporter
#11
I have received a set of new ball joints from Summit Racing, They seam to be a bit stiff but after I cleaned them out and re greased with new grease they seamed to free up quite a bit. I really like red line products so I use them. I am sure other manufactures products work well also. Just stay away from the 3 dollar stuff. Look for a temp range of at least 400F. This stuff I use is good up to 500F. Why? the heat generated by the rotors is very high and the ball joint is very close to that heat source. When I removed the original ball joints the rubber boots were hard and cracked from the heat and the grease inside looked over heated to me as it was dry and seamed to have been overheated. I will check these after every track weekend from now on.

On to the fitting, The K6136 is about 3/16s taller than the OEM piece. I will make a spacer to fit between the mounting plate and the A arm. This should place it in the original position. I also ordered a 7 degree reamer to clean up the stud hole in the plate on the bottom of the upright. The original placement left about 3/32s inch of threads in the hole. I would like to have the entire stud bearing surface in the hole with maybe a single thread left to be pulled into place as the bolt is tightened. More on this as I final fit the ball joints in the assembly.

I have contacted RCR about the availability of the spherical bearing retrofit piece and would be interested in at least having a look to see if I want to re fit them into my car. More on that if I get any info from RCR.

If anybody has pictures of these please post them.

https://www.redlineoil.com/cv-2-grease

https://www.summitracing.com/parts/mog-k6136

I have a supply of spacers for these and for the QA1 ball joints. There's a complete explanation of the ball joint story in the SLC wiki, here.

Let me know if you need a set.
 

Howard Jones

Member
GT40s Supporter
#12
I decided to use the spherical bearing/ball joint retrofit kits on all four corners. The parts in this kit seam to be very strong and well made. The thing I really like is that they use a shoulder bolt in the place of the ball joint tapered shaft. This piece alone must make the whole thing much stronger which is what I am going for.

The other thing is that the stricture of the spherical bearing must be less than 10% of a new ball joint. The whole car is so stiff that it is hard to say the ball joint stiffness can be felt but it's there and it can't be helping.

The last thing is the heat issue. Rubber grease boots will not survive on a track car. It's just too hot in that location. The SB's do not have this problem but they will need to be inspected and kept clean. Normal track car maintenance and just one more thing on the list.
 

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