HELP I'M STUPID! TIMING BELT CHANGE- HOW DO I FIND TDC

[RollinonZ34]

Hey to all...

How do i find Top Dead Center, and is it to be found on the #1 Piston cilinder? How do i know if it is on the Exhaust stroke or other, and which one do i do it on. I got everything to do the job ordered, and would like to know how to do this so when i get the parts, i'll be ready. Also, do i need to replace the bolts on the new idlers and tensioners, or can i use the old ones? This is my first time changing timing stuff, so i think i will just do it to stock specs, & chicken out on the 13* Retard until i know what i am doing...Then experiment, even tho Ben makes it look easy.

any input will help,
Paul

[WhiteZ34]

Look for the mark on the dampener on the crank, Its the rusty looking thing right behind the crank pully, if you cant see it rotate the crank until you can I think it is a 15mm or 18mm socket and a braker bar should do the trick. Then you want to line it up with the mark on the crank case cover. Here are some Pics. You want to line the mark on the dampener to the cast point on the cover It is #1 on the list.

Mike

[RollinonZ34]

Hey thanks White Z34, This is very helpful...especially the Pix you added.
Just to double check, these marks will only match up once when properly set, or can they match up twice...once on exhaust stroke and once on intake stroke...thats where im confused In other words, when they line up, there is no doubt that i am at #1 TDC.

Thanks, Paul

[WhiteZ34]

First remove the belt. Then rotate both sets of cams, so that the cam flats are facing up install the cam hold down tools. Then loosen the cam gears on the front head and undo the lock rings. Note- I only loosend the front gears and everything went fine. Set the crank to TDC as described earlier by aligning the marks. The front cam gears should spin freely. Install the belt, tensioner and pullies. Then remove the rear cam hold down tool.
Then rotate the crank until the rear cam flats are facing down, the front cams should not move, just the gears. Once you have the rear cams set face down, the fronts should be face up, install lock ring and tighten gears back down with the cam gear tool. Remove cam hold down from front and reassemble the motor. She should run like a champ.

Mike

[RollinonZ34]

I just wanted to say thanks to WhiteZ34!!! Your way that you explained...along with the Pix Walkthrough, helped me (someone who has never turned a wrench) change and Properly set the Timing along with all of the Pullys & new actuanator. Even though i did have some trouble with the actuator...I would set up the marks for TDC put on belt and all pulleys and everything going good. Then when i would pull out the pin on actuator it would tighten up on the belt. By not loosening the two cam sprockets on the Rear Bank, it would allow the intermediate shaft to turn and therefore turn crank via chain behind timing cover plate. This would then put the timing marks off by about 10* to 12* off retard...

The way i solved this, was to take everything back off, and set the crank about 10* to 12* ahead of the timing mark so that when i put it all back on, and released the pin...it tightened up on the belt and turned the crank to the desired mark...with a little measuring and Luck, it landed right on the money! Now, the car cranks up with turning key for a nano second, and lights up the tires like it hasn't in years, so i think it all worked out pretty good! By the way, the belt i took off had over 100,000 miles on it so im pretty lucky that it did not snap. Also the two inner intake cams were off by a pretty good bit needless to say from the old belt stretching, as when i took off the cam carrier covers to expose the cams, they were no where near even like they are suposed to be. Thanks again, as there is no way to get to the rear cam sprockets (at least not easily) and your way of just breaking the front sprockets loose worked good, as long as you set crank for the movement from the actuator movement of the belt.

Let me know if you had this problem, and if so how did you correct it...maybe an easier way where there is no guess work involved... Paul

[hurricaine]

Cam timing trouble

Help,
I have followed the cam timing walk thru (blown belt) but on the cam timing I set both cam flats up installed the tool and new belt rotated 360 and both flats are up. [This is the DUH part mike said turn the rear 180 or till the aft flats are down then install the front] havent dont this yet I think I'm gonna have a stroke or somthin what am I doing wrong? this is on a 1992 waaaaaaaaaaaaaa

Thanks hurricaine

[grandprixgtp_91]

RE: Cam timing trouble

what you have to do is
1) break the cam bolts loose
2)remove the cam gears
3)take out the lock rings
4)put the cam gears back on
5)put the bolts in but leave them sticking out about 1/4 of an inch
6)lock down fron and rear cams
7)spin the engine to TDC
on either the front or rear cams take out the bolts, then re-install the lock rings and tighten the bolts back up to 80 ft/lbs, and remove the lock down tools
9)spin the engine around once and bring it to TDC so the cams you bolted up are facing upside downand on the cams that are still locked and loose now install the lock rings and tighten the bolts to 80 ft/lbs and then remove the lock down tool.

that is the proper way to time the engine.

Jake

[RollinonZ34]

Re: Cam timing trouble

Help,
I have followed the cam timing walk thru (blown belt) but on the cam timing I set both cam flats up installed the tool and new belt rotated 360 and both flats are up. [This is the DUH part mike said turn the rear 180 or till the aft flats are down then install the front] havent dont this yet I think I'm gonna have a stroke or somthin what am I doing wrong? this is on a 1992 waaaaaaaaaaaaaa

Thanks hurricaine

Sounds like you did not remove one of the Cam Flat Holders before you rotated the Crank 360*.....With both Flat Holders still on, you could spin crank all day and Cams won't move..Don't get in a hurry and let this intimidate you like i almost did...almost...ha...and make sure that you properly torque everything to specks as i almost broke off a bolt on actuator plate because i got in a hurry and did not read torque specs properly...by the way, if you don't have book there are Torque Specs on this site somewhere that you might want to print out...Very Helpful... also, if you snapped a belt, i hope that it was not at high RPM as i think you might have other problems to look forward to.

[hurricaine]

Hey guys thanks for the help,
grandprixgtp_91
the crank is in TDC when I put the cams to face up where should I be if I'm not soposto be here until step 7? followed steps 1-6 6a I installed the new belt here then step 8 (didnt remove the rear sprokets only the front) step 9 1 full turn crank timing mark to timing mark and the rear cam flats are still facing up [the front freewheeling and still locked up]?

RollinonZ34
Cam banks up lock down with the tool, front bank sprokets loose #1 TDC install belt remove rear hold down tool rotate 360 and the rear bank cams are still facing up the forward cam bank is still locked up (read above about the rear cam carrier scarry) outta the 3 inch belt or so I had about a 1/4 left I think it slipped time @ idle
Sorry to be so dumb but I must be missing a step somewhere thanks for your help

Thanks for all the help

[RollinonZ34]

The proper way is the way that grandprixgtp_91 said to do. However, even if you do it like WhiteZ34 and i did it, it should and will work. My tires will light up to prove this I still do not understand why your rear bank cams will not turn though!!! If you only bust loose and loosen the Front Bank Cam Sprockets, after you have turned ALL 4 Cams to Flats Up, and then put Cam Flat Hold Down tool on (Both Banks) before you take off the old belt, you should not have a problem. With Flat tool on (Both Banks) put on the New Pulleys, and Belt. If you did not loosen Rear Cam Sprockets, at this point you would now take off the Rear Cam Flat Hold down tool and rotate (clockwise) the crank 1 full turn back to the timing mark. The Rear Bank Cams "should turn and now be facing Down"... You would then recheck timing mark with flashlight and if ok, tighten Front Cam Sprocket Bolts and take off that Cam Flat Hold down tool. Just recheck first, (before you tighten the Front Bank Cam Bolts) the timing mark after you pull the pin on the actuator, as this is where i had the problem. when it engaged and tightened the belt, it would move the Crank and advance the Timing mark about 10*...If your Rear Cams do not move when you turn the belt via Crank after you have removed the Flat hold down tool???? i can't tell you why this is happening....Might have some internal problems from when the Belt snapped???Paul

[grandprixgtp_91]

ok, if you did not break the rear cams loose then,
1)make sure that both hold down tools are in place and tight
2)install the belt
3)install the tensioner and put tension on the belt
(this is why i dont like leaving the rear cams unbolted, because the belt is not going to fit perfect inbetween the intermediate shaft and the rear cams, when you take the tools out they will move slightly.)
4)make sure the engine is a t tdc
5)take out the rear hold down tool
6)spin the engine once and bring back to tdc
7)tighten the front cam bolts
remove the front hold down tool

now you should be done. but it wont be perfect because of the rears, it might run, but it wont be perfect.

Jake

[WhiteZ34]

Hey RollinonZ34 I had the same issue here with the gears moving but I compinsated in a similar manner. I didn't even think to tell you that sorry man. I had done the belt while I was in changing the head gaskets and the belt was the least of my frustrations. But anyways I can say that my car runs great as well.

[hurricaine]

Thanks for all the help but now I'm worried so hears the story so far
(1) engine running rough [timing belt was changed 20,000 miles ago]I removed the cam covers for inspection found onlt 1/4 of the belt left suspect outta time.
(2) followed cam timing picture walk thru
(3) couldn't rotate the crank to align the cam flats,I think the rear cams were face up and I moved the front to face up.
(4) Installed the cam flat hold tools front and rear
(5) pulled only the front cam gears removed lock ring reinstalled.
(6) Rotated the crank to TDC intermediate is at the 6Oclock position
(7) Installed new belt pullies, tensioner
( Removed the rear cam flat hold tool rotated the crank 360 rear cams turn but are face up (same place I started) what is wrong and how can I correct this problem ???
Note-rear cam bolts not broken loose and at TDC original rear cam alignment marks are still aligned.
This is where I am stumped and am unsure what to do I just wanna make sure before I really screw somthing up Bad
Thanks guys sorry for the headache

[RollinonZ34]

Yes, it sounds like your pulleys were bad, or not torqued properly to let your belt get that tore up...or maby the actuator went bad and did not put the proper tension on the Belt... As far as the Cams being back up after you turned Crank 360* ...makes no sense! I am assuming that you do know that 360* is 1 full turn around on the Crank. could be that you are missing the mark on the Crank on turn, and accidently going around twice...just a thought as i put the flashlight on crank every time i turned crank even a little bit...just to make sure i did not miss it! I am also assuming that this is a 3.4 DOHC motor, as you have not stated what year, or kind of car it is! You also say that you ligned up the flats on rear by turning the Crank, which means that belt must still be on....I would and did turn these Flats up with a socket (15mm) and ratchet, after the old belt was off. they might be off a small amount but the Flat tool will pull them into place together when you tighten it down. Then once Both Flat tools are on, & you have loosened front Sprockets so that they will turn freeley, turn Crank to TDC & put on New Belt, actuator, and pulleys. Now remove Rear Flat tool and turn Crank around 1 time...Now your Rear Cams Should be facing Down & Front Cams still be facing up...If your rear Cams are still facing up like you say, there is a problem that is over my head...cause i sure ain't no mechanic, but i did mine & works good.

Also, forgot to mention as you said that you could not turn Crank to line up...Remove Spark Plugs and it will turn a little easier...Good Luck...Paul

[hurricaine]

1992 3.4 dohc
engine set @ tdc tried on compression stroke and exhaust stroke no change new belt installed removed rear flat hold down tool turned crank 360 or 1 full turn tdc to tdc the rear cam flats are still up (the rear cam flats are turning in sink with the crank. 1 full turn of the crank the rear cam also completes 1 full turn IE,,, starting with cam flats at top =cam flats on top after 360 or 1 full turn should be facing down WTH????

This pig might be on its way to the shop and the for sale lot shame had this car new with 13 miles on it when I bought it only has 92,000 now