Valve adjustment

[warrenpfo]

Right so i have the rocker cover off and all cleaned up with a new gasket ready to go. The mating surface is clean and free from contamination but whilst in there i thought i would tackle the valve clearance... and this is where i have hit a brisk wall.

Below are a few pictures of the inside any comments welcome as to the condition. The engine could do with some cleaner on the next oil change but otherwise i think it looks clean and good. There seems to be so glazing or shiny bits on the cam shaft which i have a picture of and wondered if this was normal.

Oh and the manifold looks nice and clean too which is pleasing but i guess no EGR is a big help there.


2 sec will upload pictures

 

[warrenpfo]

 

[Towpack]

Can't see anything out of the ordinary TBH. The 'shiny bits' on the cams looks like normal wear rather than glazing. The black deposits on the underside of the cover could be a sign of extended oil change intervals. Had bad experiences in the past with engine flushes or cleaners so can't recommend them personally. Many 10000's miles left to come me thinks.

 

[warrenpfo]

Thanks. The cover has cleaned up a treat. I will continue to use synthetic oil which should over time help clean up. All it needed was a wipe with a rag nothing major.

If anyone could walk me through valve clearances that would be great as I am not familiar with rocker arms but rather standard valves.

Even reading the FSM is confusing me.

 

[Towpack]

As stated in the FSM, it is critical that you support the valve bridge with a spanner when loosening/tightening the valve bridge lock nut so the bridge itself is not subject to any twisting force.

1. Loosen the VB locknut and back out the adjuster until it's clear of the top of the valve stem.

2. Loosen the rocker arm locknut and set the gap to .2mm in, .50mm ex using feeler gauges and tighten the locknut.

3.Check the rocker arm clearance you've just set does not change when you loosen the adjusting screw on the VB (it shouldn't change if you backed out the VB adjusting screw initially in step 1).

4.With the feeler gauge in the rocker arm, tighten the VB adjuster until the gauge just starts to bind and tighten the VB locknut (DON'T FORGET THE SPANNER!)..

5. Loosen the rocker arm locknut again and re-adjust the rocker arm clearance with the feeler gauge and tighten the locknut.

An unusual procedure on a tappet setup I've personally not come across before but STILL less hassle than shims IMO.

 

[warrenpfo]

Thanks, I will walk through it tomorrow morning. Fingers crossed no adjustment is required.

Am I correct in assuming no 1 is closest to the grill and the large rocker arms are the exhaust and the small the intake??

 

[Towpack]

No.1 cyl is front. Large rockers are inlet, small exhaust.

 

[Dave2000]

I agree all looks ok in there but a little tip, once you have the rocker in position to adjust (no load) rotate the roller at the opposite end of the adjuster and look for flat spots, very rare on the 80 but does happen, occasionally after the owner or previous garage used engine flush (note Towpack comment) a roller gets jammed/stuck in one position, after quite few miles the roller wears through and collapses, I have seen it twice on an 80 but IIRC 7/8 times on the Mitsubishi Pajero 2,5 TD?regardsDave

 

[warrenpfo]

Ok here goes....

First is the below line TDC mark?

If so on lining up the mark up and then inspecting the crank shaft TDC mark as I have the timing belt cover off its 2mm out. Am I to assume this is ok or should I go off the crank shaft TDC mark instead.

 

[warrenpfo]

No matter which TDC mark I use unless I "lift" (to take up the slack) by hand the rocker arm and then "lift" the contact (the round thing that swivels) of the rocker arm with the valve bridge with my nail there is no way I am getting a feeler gauge in there. The contact point rotates and seems to be "sprung" but it can't be as this would always apply pressure to the bridge and thus give a false reading on the feeler gauge.

 

[Dave2000]

Try going between the end of the adjuster bolt and the valve shim.

regards

Dave

 

[frank rabbets]

You are checking the valve clearance that way Warren. It's difficult to get the feeler in even when the gap is correct. You should loosen off the rocker nut, unscrew the thread to open the gap wide, insert the gauge and then adjust the gap until you have a tight sliding fit. Then remove the feeler.

 

[warrenpfo]

Thanks all I just dove in and did each one as required. It's a bit scary first time round but have done it it's a very easy job if not a little time consuming.

All done and ready to reassemble.

 

[Dave2000]

Oops apologies, would have helped if I had looked a little closer Warren I was thinking valve top hats.

Regards

Dave

 

[Towpack]

As I mentioned in a post above. this is the first engine I've come across with this 'valve bridge' arrangement although I've seen roller cam followers on other engines, including big commercial diesels designed to last many 100,000's if not 1,000,000's miles. A very robust looking setup on the 80 which bares testimony to the life expectancy Toyota placed on these engines IMO.