Hydraulic head timing

[uscgmatt]

Has anybody removed the hydraulic head without lining up the timing mark? I just f**ked up and did, now I am trying to figure out how to line everything up to install the new one. Thanks for the help.

 

[Parker2]

If you havent turned the engine over or moved the gears in the Head you may be able to put the old one back in and then line up the timing marks before removing it again.

Good luck.

 

[uscgmatt]

The pump gear has turned unfortunatly. Is there a mark on the pump gear to align with the hydraulic head gear in case this happens? I'm hoping you can bring #1 to tdc and install the hydro head, but I cant find any info in the TM's about this. I'm about to be bald.

 

[derby]

You must have had a time getting it out. the gear has a spot in it that is missing some teeth that let's it pop right out. I would inspect the head,and drive gear for damage. then i would get the proper tm and follow that. TM 9-2815-210-34-2-2 section 5 pages 168-182 You will not be able to get the right timing if you put it back in without the proper settings ! Why did You remove it?

 

[cranetruck]

To check the timing, you need to watch the marked gear teeth, visible in the "windows" on the IP (image below). They must line up with the timing mark on the damper. The crankshaft makes two turns for every one turn of the IP drive shaft.

Didn't you have the marked tooth aligned in the window below the HH to remove and replace
it?

 

[uscgmatt]

You must have had a time getting it out. the gear has a spot in it that is missing some teeth that let's it pop right out. Why did You remove it?

I noticed above the pump gear there is a washer with only 1 half circle cut out. Apparently both times I removed the head this lined up. My first head went bad.
Cranetruck, thanks for the pics.

Didn't you have the marked tooth aligned in the window below the HH to remove and replace
it?

I looked through the IP TM and did not see any info regarding timing for the head, so I um... just took it off. Then figureing things out I moved the engine messing with the timing. Now I have the stuff lined up and in. It runs above 1000 rpm but wont idle. Either its 180 out or just air in the lines.
Its time to buy paper manuals or print out the pdf ones, cause I always miss stuff on the puter.
Thanks for the help.

 

[uscgmatt]

TM 9-2815-210-34-2-2 section 5 pages 168-182

I thought I had all of the manuals . 1 more to the list. Thanks you.

 

[m-35tom]

just line up the notch in the plate that covers the drive gear. line up the head gear with the red tooth and pointer. if the red is gone it is the tooth with a fine line scored in it. if it won't idle you may have a bad head as at low rpm a worn plunger will not open the injectors. warning: none of the timing marks on damper or under the little plate have anything to do with timing the hyd head. it either runs or it does not there is no such thing as 180 out.

 

[Keith_J]

just line up the notch in the plate that covers the drive gear. line up the head gear with the red tooth and pointer. if the red is gone it is the tooth with a fine line scored in it. if it won't idle you may have a bad head as at low rpm a worn plunger will not open the injectors. warning: none of the timing marks on damper or under the little plate have anything to do with timing the hyd head. it either runs or it does not there is no such thing as 180 out.

Exactly. The timing marks on the crank need to be aligned WITH #1 in TDC firing, not exhaust. You will have to turn the engine over with the front valve cover removed. Once you see the crank timing mark, note the movement of the valves while slowly turning the crank. If the valves move, rotate crank another turn, then position crank timing marks aligned.

Now you can align the timing mark on the IP with the drive gear. BUT you may have difficulties meshing the gears PERFECTLY. This is why the IP front drive gear can be adjusted.

 

[uscgmatt]

Hopefully I got the timing close. It runs smooth but when you let off the gas rpm drops low then returns to normal idle.

if it won't idle you may have a bad head as at low rpm a worn plunger will not open the injectors.

Guess its time for another head. This time it should be an easy swap.

 

[clinto]

OK, I need some clarification on timing one of these.

Backstory: My '87 M35A2C w/LDT was brewing it's own oil. Tested the booster pump right before 13SSGR and found it was leaking, so I replaced the seal. Truck continues to brew it's own oil, so now I am removing the flame heater & replacing all the HH o-rings (FDC already bypassed).

I read the TM and some of the threads about it and thought I had all my info. Rotated the engine around until the red mark was near the pointer, removed the head and then had an accident where I moved the gear on the HH. And of course, I can't remember exactly where the red/scribed tooth was relative to the pointer.

So how do I retime it?

I see in the TM for troubleshooting the LDS-465 Multifuel that it says "With the LDS-465 timing pointer on the harmonic balancer lined up with the pointer, check to see if the timing mark on the advance unit hub is aligned to it's timing pointer. If these are lined up, (paraphrasing) check the scribed/red tooth on the HH and if it's visible, the IP is timed correctly".

If it's visible? It's probably visible for 40° of rotation? Heck, it could be 10 teeth off and stilll be "visible"!

So now, I am not sure I have the HH back in place in the right tooth. I could be off 1 tooth in either direction.

How do I verify I have it timed correctly? I see the above posts (#5) saying to get the engine at TDC on the compression stroke to see if the scribed tooth is one tooth off, but how can that be seeing where my crankshaft is relative to TDC? This is where I am at now:



I know I am close on the HH teeth, so if I rotate the engine around to TDC, then the HH teeth will be way off and I won't be able to remove and re-time the HH.

What am I missing?

 

[gimpyrobb]

Calling now.

 

[doghead]

Please post your phone conversation, so we can all learn...

 

[welldigger]

Set engine to tdc on #1 with the mark on the harmonic balancer and pointer lined up. Pull the small square timing cover on top of the pump and make sure the mark is lined up with the pointer in there. Then look in the hole where the hh should be and you should see the edges of a thin piece of metal covering the drive gear. That cresent cut out should be symetrical on either side of the gear. Then line the red tooth on the HH with the pointer and drop it in. You may have to shimmy it back and forth a bit but it should drop in. Don't force anything. The HH only comes out and goes back in one way.

 

[Floridianson]

[QUOTE=welldigger Then look in the hole where the hh should be and you should see the edges of a thin piece of metal covering the drive gear. That cresent cut out should be symetrical on either side of the gear. Then line the red tooth on the HH with the pointer and drop it in.

Thats close but the crank and IP timming will not be dead on when the head is put in or taken out right. If for shure the crank is on mark and is the TDC stroke for #1 and the IP timming mark is on then by rotating the motor off the marks alittle the cut notch on the quill gear show it's self. Then install the Head pointer dead on pointer. Then when the crank and IP marks are dead on the Head will be one tooth to the rear. The last pic on the post looks like it is one tooth to the rear and would be correct if the crank / ip was correct.

 

[gimpyrobb]

Please post your phone conversation, so we can all learn...

Like your Austern Western bed thread-adapter PM?

 

[Floridianson]

I do believe if if the IP pointer is dead on the Ip gear will have to move just a little little counter clockwise if you were standing in front of the motor. Then the quill slot should be good to go.

 

[clinto]

Ok, so I just put it all back together and tried to start it and it definitely will not run. It will run on silicon as long as I sprayed into the intake but as soon as you take it away it dies.

Since I had it running for several seconds, I'm gonna assume I don't have any issues with air or the system losing it's "prime".

I guess I am going to turn it over and get it to tdc on the compression stroke and see where the scribed tooth is and try to find some kind of baseline.

 

[doghead]

Confirm tdc with the valve cover off.

 

[Squirt-Truck]

Clint,
Confirm that the clearance shield is in place on the quill shaft gear.
That cover will prevent the removal and reinstall of the head EXCEPT at the designated timing location.
That location does not align with the balancer or governor timing marks. it is just past.
The scribe tooth will align with the reference pointer and two full tooth slots will be exposed, see second picture in your post.
Now if that cover is not moving with the gear then.......another issue.