Kraton Kraton 6S EXB Diff Shim Set to Open Diff - Beware

[parcou]

I could be off on the title so please correct me if I am wrong with the following

My K6S EXB came with an LSD rear but I want to try an open diff to judge the difference in performance. The kit is ARA311094.

I followed the diagram to the letter but found after I got it all together and turned the outdrives they did NOT turn. They were locked and if I backed off the 4 screws a bit it would turn until I tighten again. I think I read where someone could have been @jondilly1974 to use your own shims and not Arrma, JD sorry if this was not you and I misquoted.

The issue with kit ARA311094 if you take:
larger shim right above the o-ring + spacer = ~2.06mm (shim in the middle was between the spacer so had no play in the height)
The spacer sat on the large shim to it added to the overall height. It took me a min to figure this was the issue

Stock with the LSD stars:
stars (all 3) + large shim = ~1.94-1.96mm (again the other small shim is between the stars so does not add to the height)

To fix the issue, I needed to remove the large shim so the spacer could sit flat on the diff bottom and not in it. What I needed up with:
spacer + 0.1mm shim = ~1.96-1.98mm

ARA311094 kit says the spacer is 1.9mm in height but I never got that anytime I measured it on I got ~1.86-1.88mm. The 0.1mm spacer I used was from a TRB shim kit a 12x16.01mm and all that came to the ~1.96-1.98mm which was in the range of the OEM with the star LSD plates.

How I placed the 12x16.01mm shim was sun gear then placed the shim under the bottom since there was a lip on the sun gear. Then placed the spacer onto the sun gear to sandwich the shim.

I am open to any corrections if I got anything wrong, but I hope it helps someone else or others add to correct what I found This gave me a very smooth rear open diff. FYI - it did work without the 12x16.01mm however I just did not feel any gear resistance when I turned the diff, felt nothing on the inside. Adding .01 did give the slight feel I was looking for and felt more like when I finished an Infraction diff to have the slights, faint internal tick.

 

[mxfan69]

As with all “shimming of diffs” it is going to take a combo of various sizes and also sometimes multiple attempts to get it “just right”. I know you already know this and are looking for solid input as to your exact set up. I cant say 100% for sure, but have seen a couple youtubers do just what youve done, and if memory serves correct they end up with a very similar stack combo.

 

[parcou]

As with all “shimming of diffs” it is going to take a combo of various sizes and also sometimes multiple attempts to get it “just right”. I know you already know this and are looking for solid input as to your exact set up. I cant say 100% for sure, but have seen a couple youtubers do just what youve done, and if memory serves correct they end up with a very similar stack combo.

You are spot on. My mistake was going into this thinking the kit they made to convert to open for the 29mm diff was going to be a cakewalk. I should have known better with Arrma. Glad I had different shim sizes to play with.

Thx

 

[HZRDOS]

Thread 'Building a stronger 29mm diff' https://www.arrmaforum.com/threads/building-a-stronger-29mm-diff.43971/

 

[jondilly1974]

Building diffs is always a case by case scenario. You’ll never find two are exactly the same. This is why shims exist. To make up for the machine tolerances. You will get used to the feel of a good diff over time. Give that one a rip and see how it feels. Adjust as necessary.

 

[mxfan69]

Thread 'Building a stronger 29mm diff' https://www.arrmaforum.com/threads/building-a-stronger-29mm-diff.43971/

Oh thats a good one there. I like his thought on the additional tab support as that makes sense from a shear strength point.

 

[HZRDOS]

Oh thats a good one there. I like his thought on the additional tab support as that makes sense from a shear strength point.

After I sheared the tabs off 2 diffs, had to think of some way to make better.

 

[mxfan69]

After I sheared the tabs off 2 diffs, had to think of some way to make better.

LOL I just caught that the OP of that thread IS YOU !!! Good job buddy

 

[parcou]

Thread 'Building a stronger 29mm diff' https://www.arrmaforum.com/threads/building-a-stronger-29mm-diff.43971/

Thank you!

Reading your reply to your post here:
https://www.arrmaforum.com/threads/building-a-stronger-29mm-diff.43971/post-609054

Confused on that reply. I am taking rear LSD and made it a full open. I have the large thick shim in place and another 12mm shim as in my OP post.

My large shim measures close to 1.88 almost 1.9mm alone where yours is 1.8. So it looks to me mine is fully covering the tabs. Are you still saying I need a star to protect those tabs need something in there? Looks like in that reply you told JD no.

Maybe I am misunderstanding, sorry. I appreciate your sharing.

 

[GRIFFINJ]

I’ve used that conversion on several EXB diffs and have had ZERO issues. Are you removing all 6 LSD plates?

 

[parcou]

I’ve used that conversion on several EXB diffs and have had ZERO issues. Are you removing all 6 LSD plates?

I have so far removed them all....the RC is still on the bench I just did my part Sat this is what I am trying to get clean. But I think he used one of the LSD plates that has an insert that goes in between the tabs to help protect the sun gear. So this I have not done if that is what you and he are doing.

 

[GRIFFINJ]

I removed all 6 plates and the kit works perfectly. Smooth as butter and takes a beaming. Haven’t had any diff issues since converting

 

[parcou]

I removed all 6 plates and the kit works perfectly. Smooth as butter and takes a beaming. Haven’t had any diff issues since converting

If I remove all 6 plates, yes it works. But I have no tab protection per his thread/post

@HZRDOS if I use his method in order to protect the tabs. I have a 1.9mm spacer from the EXB kit. If I take the circle LSD plate and place it with the kit spacer I then have 1.9mm + 0.6mm which .6 is the circle. Doing that to both ends adds too much and it is locked and the outdrives will not turn. Maybe since he purchased his spacer and was not from the Arrma EXB kit...?? IDK. Maybe like @jondilly1974 said no two are the same I would like to protect the tabs but with the large 1.9 spacer I am nowhere close to 1.8mm he is getting then I am at about 2.48mm something like that this or his method is not working for me. Unless I am seeing something wrong.

 

[GRIFFINJ]

I guess I’m lost with what “tab protection” refers to

 

[parcou]

I’ve used that conversion on several EXB diffs and have had ZERO issues. Are you removing all 6 LSD plates?

HZRDOS post he put above...
https://www.arrmaforum.com/threads/kraton-6s-exb-diff-shim-set-to-open-diff-beware.45720/post-637767

Those are the tab right under the sun gear. Like you I had no idea this could happen until he posted that.

Let me make a correction I do believe JonDilly all this is different. With the kit, I cannot use it out the pack as you did. The larger flat shim adds the 0.2mm the spacer sits on that makes it all bind when I put it together. So like your setup I have to remove the two larger shims out of the kit on each side and replace them and add 0.3mm smaller shims for each side and I get a 1.96mm and it all closes up, no bind and no LSD plates. No tab protection if that is still a real concern...?

 

[jondilly1974]

I think you’re correct that the Arrma 1.9mm shims are too thicc to use the @HZRDOS method. You will need thinner shims. The shims @Rcproponent sent me that he bought from MMC are various thickness, 0.1, 0.2, and 0.5 if I remember correctly. I would suggest you pick up some 0.1 and 0.2mm shims if you want to be able to precisely dial in some open diffs using the @HZRDOS method. I have t yet broken the tabs on the back of my sun gears, but I will likely use his method going forward for all of my EXB diffs.

 

[HZRDOS]

Correct. I don't use the Arrma shims. I have the info for the shim I used in the thread.

 

[parcou]

Correct. I don't use the Arrma shims. I have the info for the shim I used in the thread.

Thx my friend

I did look at the precision brand website and did not see item #26759 and did a web search but no luck for me. Do you have a direct link from your purchase? If so can you send it to me so I can use a SOLID spacer preferred.

In the meanwhile, I did get a solution to match the 1.9mm spacer that came with my EXB Arrma shim pack and closely match the stock LSD plates and the bottom flat shim for 1.92mm combined on the stock.

TRB Shim kit M12x16x0.5 x2
TRB Shim kit M12x16x0.3 x1
LSD circle plate 0.6mm

All gave me a 1.9mm and now adds the tab protection you mentioned. @HZRDOS next change I would like a solid spacer if you ever find that link please share. Thx Sir!

 

[HZRDOS]

Thx my friend

I did look at the precision brand website and did not see item #26759 and did a web search but no luck for me. Do you have a direct link from your purchase? If so can you send it to me so I can use a SOLID spacer preferred.

In the meanwhile, I did get a solution to match the 1.9mm spacer that came with my EXB Arrma shim pack and closely match the stock LSD plates and the bottom flat shim for 1.92mm combined on the stock.

TRB Shim kit M12x16x0.5 x2
TRB Shim kit M12x16x0.3 x1
LSD circle plate 0.6mm

All gave me a 1.9mm and now adds the tab protection you mentioned. @HZRDOS next change I would like a solid spacer if you ever find that link please share. Thx Sir!

I order them from McMaster-car
https://www.mcmaster.com/shims/

Place all the parameters in the menu on the left, and bam....any size shim you want.

 

[Rcproponent]

I now also use the @HZRDOS method… I think.. lol I remember seeing his write up on it… not sure if I’m doing it exactly as he is but it’s similar.. I wanted protection for the tabs too.

I used I wanna say (2) .2 and (1) .5

I just did this the other day but cannot remember