1HZ Valve adjustment

Submitted: Wednesday, May 17, 2006 at 18:04
ThreadID: 33988 Views:6853 Replies:6 FollowUps:2
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I am looking at re-shimming a couple of valves on my 1HZ engine. The Gregorys book recommends using a Special Service Tool (SST) to push down the cup so I can get the shim out. Does anyone know what this SST looks like? The book also says I can use two screwdrivers instead - has anyone tried this? Also the Gregorys formula to calculate the thickness of the replacement shim gives a different answer to the shim calculator on the LCool web site. I think that Gregorys has an error in the formula! Is there anyone familiar with this that can help me?
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Reply By: Peter 2 - Wednesday, May 17, 2006 at 19:00

Wednesday, May 17, 2006 at 19:00
The SST looks like a small G clamp with a couple of ridges on the underside to push the cup down and allow the shims to be lifted out.
We found that once the clearances were set once (they were way out from the factory on 6 engines we did) they didn't need doing again for well over 100k.
We used the factory manual. I do have a photocopy of the relevant pages.
You will probably only have to buy a few shims as you can swap them around to acheive the correct result.
We bought the tool between a few owners and the rule was any unneeded shims were left in the box for the next person.
From memory I used to measure them hot, then sit down and work out what had to be added or subtracted to each one to get the required gap.
Took a bit of fiddling but the engines ran way smoother and pulled better after doing them.
AnswerID: 173186

Follow Up By: Mikee5 (QLD) - Wednesday, May 17, 2006 at 19:29

Wednesday, May 17, 2006 at 19:29
Thanks for replying.
When you did the shims, did you go for the min, max or in between clearance? Inlet is .15 to .25mm, Exhaust is .35 to .45mm? Do the shims come out easily? Gregorys recommend a magnetic pencil then say you can use a small screwdriver! The last time I did a set of valves it was on an FC Holden! Is it possible you can email or fax a copy of the pages from the factory manual? I have the Gregorys but as I said I am not sure I trust it!

FollowupID: 429034

Follow Up By: Peter 2 - Wednesday, May 17, 2006 at 20:50

Wednesday, May 17, 2006 at 20:50
I've searched here and I suspect that I gave the photocopies to the same bloke that got the workshop manual so can't help there.
Mikee makes a good point but the 1hz shims come out pretty easily, I just used a magnet.
For what it was worth I asked at three local Toyota dealers (northern sydney)about getting them done and all three dealers said they never do them and didn't even have the tool!!! so much for doing services correctly!!!
We aimed for getting pretty close to the centre point of the gap range as we figured that then we would be pretty close to optimum.
I remember when I did mine the first time some were so far out that it was a wonder the engine went as well as it did.
FollowupID: 429054

Reply By: Toytruck - Wednesday, May 17, 2006 at 20:31

Wednesday, May 17, 2006 at 20:31
with all due respect intended, it sounds to me as though you are entering into unchartered territory for your good self. I spent 7 years of a previous life building some of the best race engines various aspects of motorsport has seen in NSW and would recommend leaving this one to the experts. The shims can, and I mean sometimes, can be very tricky to get out. Then, if you get them out but get the measurement wrong and install the incorrect thickness and fully assemble, start the engine and have a rattle, pull it all back to bits and repeat the process.

If the last experience you had was an old Holden........leave this one to the experts. It is worth the expense.

Once again, no disrespect intended to you.

AnswerID: 173206

Reply By: Member - Mal B - Wednesday, May 17, 2006 at 21:12

Wednesday, May 17, 2006 at 21:12
i agree this is a job for the experts also should be done on a very cold motor safe driveing mal
AnswerID: 173220

Reply By: Topcat (WA) - Wednesday, May 17, 2006 at 21:36

Wednesday, May 17, 2006 at 21:36
Hi Mickee5, have emailed you the relevant pages you require, but I adsvise caution as mentioned in above posts-unless you have experience in doing this it is not worth the trouble if you get it wrong!!!!!. Best of luck.
AnswerID: 173231

Reply By: Off-track - Thursday, May 18, 2006 at 00:23

Thursday, May 18, 2006 at 00:23
I disagree - it is a very simple process that is outlined in the Gregory's manual. I used the screwdriver method but you may need the use of a third hand to make things easier.

Most important thing to remember is measure, remeasure then measure again. Then crank the engine over a few turns and measure again.
AnswerID: 173268

Reply By: Andrew-rodeo - Friday, May 19, 2006 at 00:54

Friday, May 19, 2006 at 00:54
You can buy the tool from your local toyota dealership, it doesnt cost a lot. It is easy to use and wont damage anything. the easiest way to calculate the clearance is to subtract the current clearance from the maximum clearance allowable to give the amount to be machined off.
Hope this helps
AnswerID: 173462

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