Jump to content
The mkiv Supra Owners Club

Subframe bolt disaster


Ian C

Recommended Posts

So I went to tighten up my subframe bolts yesterday, and the big buggers near the rear of the front subframe needed about an eighth of a turn. I then went to the 17mm nuts and found one on the driver's side that needed a fair bit of doing up. Aha, thought I, here we go, this is the cause of my handling issues. After about three full turns I started to get suspicious that something wasn't right.

 

Remember those flat headed bolts on the chassis legs by the inside of the suspension turrets? The ones that sit on the banana-shaped metal bracket? They are the other end of the subframe bolts. And the one I was working on was merrily turning as I tried to tighten the nut up underneath. Ordinarily this would just be a pain in the backside as you'd need someone holding a spanner on the bolt head while you tightened away. With this though, the blasted bolt picked up the bracket and mangled it :mad:

 

I think Scooter asked a question about these plates a while back but I can't find the thread. I'll have pics tomorrow, I left the camera in the garage and I'm at work.

 

Now, this bracket seems to not only act as a load spreader, it also stops the bolts from creeping around under load. When I marked them up with pen and turned the nut under the car a quarter turn, bare metal was exposed near the bolt head, a good 2mm's worth - i.e. the whole bolt had physically moved 2mm towards the rear of the car. Turning the bolt back covered the metal up again. That says to me the subframe can move as this nut/bolt combo turns around under load stresses, hence the handling being random.

 

I marked the bolts up again and went for a drive on bumpy roads and hit every dodgy drain cover I could, and the markings didn't move. It also seemed to drive OK, no real tramlining. But I'm still reticent about driving it with a mangled plate in there :( So I need a good one of those (it's marked RH side) if anyone has one :D

 

Let this be a heads-up to anyone else tightening their front subframe bolts :) It'll make more sense when I get the pics up.

 

-Ian

Edited by Ian C (see edit history)
Link to comment
Share on other sites

Would like to have a look at mine, got a pic of where they are on the underside?

 

Sadly no, I didn't take any pics, but when I have another attempt I'll get loads as it's a confusing mass of bolts under there. It'll be quite helpful judging by the responses, and these things need doing every 3 years or so. And not every 6 or 7 hah.

 

I've already been contacted regarding a replacement bracket and bolts set, this club is the business :D

Link to comment
Share on other sites

There is a Toyota EPC diagram but it's really quite awful at showing the right number of bolts, never mind where they actually live :)

 

Actually Ian I forgot how bad that photo is with just a steering column and loads of -------- coming down in various sections representing one bolt. I am wondering if where my friend only tightened the front one's (which cured the reverse turning knock) and not the back seeing as I get this annoying squeak at times when doing a forward sharp turn at slow speed, I had my tracking checked and that was fine but yesterday I came off a roundabout and the back end just shot out about 80 degrees to the right resulting in me doing a massive semi powerslide trying to correct it but I knocked the bloody curb although I consider myself lucky as their was no body damage whatsoever just a slight scuff on my front left wheel that needed fixing anyway. Drifting seams good fun but not when you don't expect it.

Link to comment
Share on other sites

It was only a scan through. Problem solving is 95% finding out what's not wrong so I don't mind, it's what I do :) And I'm at work hah

 

Ian is this page the useless one you were thinking of at the bottom of the first page?? http://www.turbosupras.com/pdfs/JZA80%20TSRM/MA.pdf

Edited by Graham1984 (see edit history)
Link to comment
Share on other sites

I might be under mine tomorrow, but from memory i've only done 10 bolts...5 each side

 

a cluster of 3 (19mm?) near the back of the front wheels and not far in from the sill.

2 tucked up inside the aluminium part, one of which the deep socket and extension when vertical rubs the steering rack boot and the other is I think 6" or so further towards the back (one of these bolts is I think 17mm and one 19mm NB correction both are 17mm the 19mm is the engine mount nut/bolt and is further in towards the engine than the two subframe bolts) If you look in the engine bay down past the suspension turret (drivers side) you'll see the horseshoe bracket Ian mentions and can use this as a guide to where to look for the bolt heads underneath.

Edited by Scooter (see edit history)
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.