Rear Shocks Upper Mount Bolt Size??? (1 Viewer)

[PZLCruiser]

Calling all toyo experts...

What is the bolt size/thread for the rear upper shock mounts? Mine look ugly and ill probably break them this weekend. Local dealership was no help. I dont know why I even try any more.

 

[bmac1996acc]

I can't help you with the bolt size but use rust penetrant. Both driver side came out no issue for me. One passenger side came out clean. The other started to turn easy then started to bind. I broke that one. I think the build up of rust that was on the exposed portion of the bolt that protrudes through the fixed nut caused it to bind. I would try getting a wire brush in there to clean off as much rust as possible from the threaded end of the bolt. I wasn't able to save the factory nut because the bolt broke at an angle so when I drilled it to use an exactor I was off center.

 

[IronCladLou]

I thought I knew the answer to this, but it's not blatantly obvious. I used a 14mm socket to remove mine but almost rounded off the head on one of them. A 14mm width across the flats indicates an M10 fastener (with a 1.25 thread pitch most likely) if using the JIS standard (which isn't really common any more). For ISO metric threads, there really isn't a 14mm width across the flats, but M8 fasteners are 13mm. Sooo...I suspect the fasteners are M8s. As for the length, like bmac mentions above, the extra thread protruding from the nut just ends up rusting and ruins your life, so an M8 fastener that is probably 20mm long would be about right.

My 2 yen.

 

[clownmidget]

M8-1.25 x 50-mm if I had to wager...and I assume you're talking about the two that afix the plate to the cross-member per side, not the actual pin/stud at the top of the shock body itself

 

[PZLCruiser]

right, the two bolts that hold up each mounting plate. Wow not so cut and dry as I thought it might be.

Ive sprayed them with PB blaster for a few days now so there soaking. Im thinking about going to the local pawn shop for a grinder/cut off jobber and heat up the bottom bolt just to be safe. Looks just as ugly as the top half.

 

[IronCladLou]

You got your money's worth out of that shock...

As for the length, I think the factory ones are ~25-30mm and they are plenty long enough. The total stack up is just the shock mounting plate (maybe 3mm max), the bracket on the frame (another 3 mm?) plus the height of the nut. A typical M8 nut is 6.5 mm, so the total stack up is probably no more that 12-15mm with a washer, hence my 20 mm length suggestion. I think 50 mm would be too much.

As soon as someone chimes in with the real answer I'm going to get some new ones myself...

 

[bmac1996acc]

The original bolts are not long enough if you need to get a nut on the end when going through the original nut. I dont know what the length of the bolt was that I used because I just grabbed one I already had in the bin. Just add the length of whatever nut you use to the length of the factory bolt and you should be good. I thew in a washer too for good measure.

 

[PZLCruiser]

I'm running to the parts stone now so ill get a few extra washers and different sizes. Ill take a pics and measure if I dont get excited and ramrod the job to go on a test ride.

 

[PZLCruiser]

oh yah almost forgot, thanks guys!

 

[PZLCruiser]

So I got off the rear shock bolts off last night nice and clean. Nothing broke or stripped thankfully. So the bolts turned out to be bigger than M8s. I had bought some new M8 bolts to replace them with and they were too small. My guess is that they are M10 1.25 x 50mm

Just for the record and future reference...

 

[IronCladLou]

So I got off the rear shock bolts off last night nice and clean. Nothing broke or stripped thankfully. So the bolts turned out to be bigger than M8s. I had bought some new M8 bolts to replace them with and they were too small. My guess is that they are M10 1.25 x 50mm

Just for the record and future reference...

Well, how about that, they are JIS fasteners, then (not ISO). Man, it's a PITA keeping all of these specs straight... Supposedly JIS fasteners have been phased out, but I don't know when...