MT64 rear shock noise

[GrouchyTech]

RESOLVED: solution is at the end of this post.

I have a subtle "thunk" that SEEMS like it's coming from the rear upper shock mounts--if not it's probably a passenger side rear sway bar bushing that inserts into the bar itself. It seems like the upper shock bushings do not get properly tight/compressed.

There is a thick washer that goes between the top nut and the top washer and this thick washer needs to slide over the shoulder on the shock shaft. This washer is able to be incorrectly tightened against the shaft shoulder which leaves things loose, but I've confirmed they're both installed correctly. I may add a shim washer but wanted to check if any of you with the MT64 shocks have a similar noise.

SOLUTION:
Well, I got this sorted out. There’s no clunk, no squeak/chirp, no movement, and it feels great. It’s as if Toyota knows best

You can see there’s been some movement that shouldn’t be there. So, here’s (my) solution:

Use ALL your original Toyota parts EXCEPT for the OME bottom and top washers as well as the smaller diameter thick washer that sits directly under the nut.

The OME top and bottom washers are slightly thicker than the Toyota washers, which helps preload the bushings a bit more.

The Toyota rubbers are a little taller than the OME, outer diameter is the same and so is the hole. I have no idea how they compare with regard to durometer, but they feel similar.

 

[elcie200]

Just here for moral support. My first reaction was “oh no not this again”. But good to know. I just ordered MT64.

Fwiw I had a “thunk/clang” when I installed Nitrochargers. My shop resolved fiddling with the washers. I think they put a OEM washer in? But I could be totally making that up/remembering incorrectly.

I was surprised it required any fiddling; thought rear shock would be the most uneventful install.

 

[GrouchyTech]

Just here for moral support. My first reaction was “oh no not this again”. But good to know. I just ordered MT64.

Fwiw I had a “thunk/clang” when I installed Nitrochargers. My shop resolved fiddling with the washers. I think they put a OEM washer in? But I could be totally making that up/remembering incorrectly.

I was surprised it required any fiddling; thought rear shock would be the most uneventful install.

I think I’ve narrowed this down to that sway bar bushing. I have one on order, I’ll update if that does the trick.

 

[bloc]

Is OME still shipping BP51s with incorrect rear washer stacks?

 

[GrouchyTech]

Is OME still shipping BP51s with incorrect rear washer stacks?

Hmmm… elaborate please!

 

[bloc]

Hmmm… elaborate please!

Stock has one flat and one washer with a hat, leading to the correct preload on the crossmember. For a long time, and not sure if they’ve ever fixed it, OME included two hatted washers with instructions to have the hats facing each other, leading to issues.

More here:

Thread 'Can someone with BP51 Confirm my theory? Squeak gone, now thump.'

Jan 26, 2022

I have a 2021 200 with BP51 Suspension on it. Soon after install I had a pretty annoying squeak coming from the back. I read BP51s were shipped with a bad set of washers. I contacted ARB and they sent me new washers no charge. I put them on and the squeak is gone. Shouldn't have been there in the first place but I was stoked they fixed it for me. Now it seems like there is a faint thud coming from the back. The two middle washers they sent me have collars on them. My theory is the collars might be a little too tall so when they are sandwiched there is a void between them (see diagram...

• residualboulders
• Replies: 22
• Forum: 200-Series Cruisers

 

[GrouchyTech]

Stock has one flat and one washer with a hat, leading to the correct preload on the crossmember. For a long time, and not sure if they’ve ever fixed it, OME included two hatted washers with instructions to have the hats facing each other, leading to issues.

More here:

Thread 'Can someone with BP51 Confirm my theory? Squeak gone, now thump.'

Jan 26, 2022

I have a 2021 200 with BP51 Suspension on it. Soon after install I had a pretty annoying squeak coming from the back. I read BP51s were shipped with a bad set of washers. I contacted ARB and they sent me new washers no charge. I put them on and the squeak is gone. Shouldn't have been there in the first place but I was stoked they fixed it for me. Now it seems like there is a faint thud coming from the back. The two middle washers they sent me have collars on them. My theory is the collars might be a little too tall so when they are sandwiched there is a void between them (see diagram...

• residualboulders
• Replies: 22
• Forum: 200-Series Cruisers

Hmmmm looks like that’s what happened with this one. Might just grind the raised portion down on the upper hat washers. At least until they can send the corrected parts.

 

[4gotalot]

Hmmmm looks like that’s what happened with this one. Might just grind the raised portion down on the upper hat washers. At least until they can send the corrected parts.

I tried grinding the top hat/pilot washers but the rubber bushings were still too soft to hold them in place after compression from a bump. I would recommend reinstalling the original Toyota pilot washer. If you ask ARB for a replacement washer set, they will send you the same undersized pilot washer you received with the shocks.

I had a conversation with them 1-24-2017 ( I still have my ts notes) and a few more about this "clunk" issue, they had never heard of this problem even after all of my calls and others had called them. We were also dealing with some bad batch of rubber bushings, too soft. The rubber bushings from ARB were having crush/rebound problems. The front would squeak from metal on metal. The back would have the clunk.

I just added another shock washer to the top of the stack to increase pressure to the rubber bushings until I picked up a new Toyota OE pilot washer. Then I just left the extra washer in place to fix the other bushing problem.

 

[GrouchyTech]

I'll try replacing the washer on the top (frame-side) with the original washer. Might add a thicker washer under the nut to provide some more preload after that, if needed. I was curious why they had a washer with the raised portion on both the bottom AND top.

 

[4gotalot]

The undersized aftermarket pilot washer will dislodge then clunk back into the frame mount. I have seen pictures of an auger out frame front mount and back mount. The bad batch of soft rubber bushings really made a racket with the combination of both in the back.

 

[GrouchyTech]

I had a minute after work so I quick and dirty ground-down the raised part of the upper washer and added a 3.5mm washer under the nut for a bit more preload.

They seem to be OK now, but I ordered a set of OEM washers and bushings and I’ll pop those on when they arrive— the ones I modified will definitely be rusty within a week.

 

[GrouchyTech]

It’s just strange that they are very specific about installing two of those locating washers at each upper shock mount.

Perhaps someone has already done the legwork for this: is there any difference in length between the OEM and MT64 upper shock bayonet from where the first washer sits to where the shoulder/threads start? How about the diameter? If the dimensions are identical, then it sounds like going back to the OE Toyota washer/bushing stack may be the best move.

 

[4gotalot]

I don't have the specs for the OE bayonet. Use the new OE pilot washer to ck the opening on your frame.

Remove the lower end of the shock from the mount. Reach up and grab the upper section of the shock and try to move it side to side to ck for movement.

 

[GrouchyTech]

I don't have the specs for the OE bayonet. Use the new OE pilot washer to ck the opening on your frame.

Remove the lower end of the shock from the mount. Reach up and grab the upper section of the shock and try to move it side to side to ck for movement.

I couldn’t get any lateral movement of the included MT64 locating/pilot washer after grinding the upper washer and adding a 3.5mm washer, but when you take some preload out of the bushings there’s plenty of play. I’m sure it moves around a little bit in the frame with the much higher forces of driving.

I think I’ll just go ahead and put Toyota rubber and washers on.

 

[elcie200]

I couldn’t get any lateral movement of the included MT64 locating/pilot washer after grinding the upper washer and adding a 3.5mm washer, but when you take some preload out of the bushings there’s plenty of play. I’m sure it moves around a little bit in the frame with the much higher forces of driving.

I think I’ll just go ahead and put Toyota rubber and washers on.

Will the OEM fit the OME?

 

[GrouchyTech]

Will the OEM fit the OME?

We shall see…

 

[4gotalot]

We shall see…

Here are some measurements and info about the old OME locating washers I found on my 3rd page of notes after a year on the LC. This info is from the older pilot washers and soft rubber bushings that caused a "clunk" and wear. People at ARB were very nice and appreciated the info.
You may have received an old set that was still on the shelf.

-Problem #1, indexing washer not correct pilot size
-Frame ID 29.0 mm - 29.5 mm
-OMEmu OD 26.0 mm (pilot washer part that goes into frame)
-Stk washer OD. ....
#1 fix = Correct size of indexing washer, also a thicker bushing by 1/8 inch or more rigid bushing material.
I added another cupped washer on top of stack to increase pressure until correct indexing water is installed.
Installed new Toyota OE pilot washer in place of OMEmu washers and left the extra washer on top for many years and all is well.

I take notes with a piece of paper and pencil. Most of the time I just write on my work bench surface. I do not type well.

 

[GrouchyTech]

Here are some measurements and info about the old OME locating washers I found on my 3rd page of notes after a year on the LC. This info is from the older pilot washers and soft rubber bushings that caused a "clunk" and wear. People at ARB were very nice and appreciated the info.
You may have received an old set that was still on the shelf.

-Problem #1, indexing washer not correct pilot size
-Frame ID 29.0 mm - 29.5 mm
-OMEmu OD 26.0 mm (pilot washer part that goes into frame)
-Stk washer OD. .... " " " " "
#1 fix = Correct size of indexing washer, also a thicker bushing by 1/8 inch or more rigid bushing material.
I added another cupped washer on top of stack to increase pressure until correct indexing water is installed.
Installed new Toyota OE pilot washer in place of OMEmu washers and left the extra washer on top for many years and all is well.

I take notes with a piece of paper and pencil. Most of the time I just write on my work bench surface. I do not type well.

Good info. I'm about to pull it in and install (at least) the Toyota locating washer. I have new Toyota bushings on hand so I may swap those in, too.

 

[bloc]

It’s just strange that they are very specific about installing two of those locating washers at each upper shock mount.

Strange indeed. This is a well-known issue with BPs on 200-series, and it would seem there are a ton of installs in Australia, which is much closer to home for them. We just don’t hear from those guys as much in this forum.. No idea how this persists within a company that generally does a good job of fit & finish.

 

[GrouchyTech]

Strange indeed. This is a well-known issue with BPs on 200-series, and it would seem there are a ton of installs in Australia, which is much closer to home for them. We just don’t hear from those guys as much in this forum.. No idea how this persists within a company that generally does a good job of fit & finish.

I COULD have old stock, but they were drop-shipped straight from ARB so I would think they are current.