Gtst Timing Belt Replacement

[grigor]

R33 Timing belt replacement(manual gearbox)

Select neutral and apply handbrake firmly. Put the keys in the console. (The valves will hit the pistons if someone tries to start it without a cam belt.)

You may want to jack up the front of the car; they’re so low you’ll get a sore back.

Under car:

From beneath the car, undo the setscrews and remove the plastic under engine windage tray.

Loosen the centre lock nut and back off the air-con belt adjuster.

Engine Bay:

Undo 2-plastic clips and remove cold air intake duct.

Disconnect electric plug from crank angle sensor, unclip cable from timing cover bracket and tie cable clear.

Mark position of crank angle sensor on timing cover, undo the 3-set screws and remove crank angle sensor.

Undo 2-top radiator mounting brackets.

Unclip radiator overflow pipe and tie clear.

Undo bottom radiator hose at core and drain coolant into bucket.

Undo top radiator hose at core and tie hose back and clear.

Disconnect temperature probe at plug on right side of core and tie cable clear.

Undo 4-nuts holding fan clutch to water pump and manoeuvre fan off the hub and gently rest it against the radiator core.

Carefully lift radiator complete with cowl and fan up and away.

Loosen power steer hinge bolt slightly, back off belt adjuster then remove power steer belt.

Loosen alternator bottom hinge bolt slightly, back off belt adjuster then remove fan belt and water pump pulley.

Remove air-con belt.

Undo cam belt top cover set screws (take care with rubber grommets) and remove top cam belt cover.

Select 4th gear, apply handbrake firmly then loosen harmonic balancer retaining bolt.

Remove bolt and thick washer then screw bolt back in by approx 8-turns.

For an Rb20 and Rb30, there are 2-M6x1.0 tapped holes at 70mm centres in the balancer for the puller bolts.

For an Rb25, there are 2-M6x1.0 tapped holes at 75mm centres in the balancer for the puller bolts.

Using 50mm long setscrews in these holes, and a suitable puller, pull harmonic balancer. You will have to unscrew centre bolt more as the balancer slides off. Don’t drop the balancer as the pulleys are easy to chip.

Select neutral gear.

Undo cam belt bottom cover set screws (rubber grommets again) and remove bottom cover.

Remove keyed pressed metal belt guide from crankshaft.

Replace the harmonic balancer bolt and using your Tee brace and socket; rotate the crank until each timing mark on the gears lines up with the marks on the rear cover. Intake cam mark is at approx 10 o’clock, exhaust cam is at approx 2 o’clock and crank has keyway up with mark at approx 5 o’clock. (Don’t worry if any old painted marks on the belt don’t line up with the timing marks on the gears.)

Check the new belt has timing marks painted on it. (Nissan belts have marks, some others don’t)

Now are you sure you can imagine the new belt lining up on all those marks?

OK, loosen the tensioner centre bolt and using an Allen key, rotate the tensioner away from the belt as far as it will go, then nip up the centre bolt.

Slip off the old belt.

Now you must decide about water pump, tensioner and idler.

If you replace the idler, locktite its retaining bolt before torqueing it back up. NSK 56TB 2801 B01 ENSL 309

If you replace the tensioner, take care positioning the spring correctly, then rotate it away from the belt and nip up the centre bolt. NSK 60TB 0683 EA7L 806

If you replace the water pump, make a template gasket to keep for future reference. Certain models move that 6mm setscrew near the centre top.

The Nissan belt can only go on one way. It’s clearly marked and really obvious if you’ve got it back to front, as the painted marks will be way off.

New belts are a bit tighter to fit and you’ll need a hand to get all the marks lined up. I use a mirror to see the crank gear mark. If you’re having lots of trouble, chances are you haven’t rotated the tensioner away far enough.

Once it’s on, loosen the tensioner centre nut and the spring will apply a slight load to the belt.

Now have a really close look and be dead sure the marks are all correct.

With the car in neutral, use the balancer bolt and your socket Tee brace again to rotate the engine about 6 times to settle the new belt on to the gears.

Now this is what I do. With the tensioner still loose, slowly rotate the engine so that the belt is under tension (on the exhaust side) and simultaneously nip up the tensioner centre nut.

The belt should now be tensioned.

Torque up the centre nut on the tensioner and remove the balancer bolt from the crankshaft.

Check the key hasn’t fallen out of the crankshaft, and then just put it all back together.

Locktite the harmonic balancer bolt when torqueing it up.

Be very careful you don’t drop anything down the cam belt covers during assembly.

The crank angle sensor drive can only fit one way on the camshaft spline, so take care to line this up when re-installing.

After you get it started, purge all air from the cooling system including turbo, heater etc.

Check your ignition timing with a timing light connected to number 1 coilpack harness, not the Nissan loop at the igniter module.

You might hear a slightly different cam belt noise if you fitted an idler or tensioner until the bearings have done some work.

First time takes a max of about 4 hours, and you may need assistance slipping on a new belt. I can guarantee that blood will be spilled.

Rb20 and 30 puller, made from 10mm thick plate cut to this shape to clear the casting lumps on the balancer.

Rb25 puller similar but with 75mm hole centres.

NOTES:

Tensioner changes: NSK 60TB0683 has replaced NSK 60TB0732A

If your engine has bigger cams, tension the belt slightly more. I found the different cam load caused the belt to slap noisily against the tensioner at around 1800rpm; at any other revs it was quite normal.

The Rb26 has the balancer bolt tensioned at 45.5 to 47.5KgM (330-340ft lbs)

The other engines have a smaller headed bolt and it's tensioned to 14.5 to 15.5kgM. (105-115ft lbs)

Edited November 3, 2007 by grigor

[Simon-S14]

thats a really good guide for those who dont know... but could you please fix up the formatting of your guide so its a bit easier to read it all... some numbered spaces or something would work a treat

[RipNGrip]

The engines manuals will give u diagrams if u are unsure about all the names of certain parts.

[Sumo]

Awesome DIY

Half way through - waiting for tensioner and idler to show up tomorrow

Cheers

Sumo

[ICER33]

not replacing the belt just putting in a cam gear. is there a way i can hook the belt back up wihtout havingt to go through such a painstaking process. the car is only doen 70,000 kms so there is no point in changing the belt as it is fine.

any help would be great

[Proximity Motorsport]

actually u would probably be better off to change it for that $70 and that peace of mind. Then think.. u wnt have to do it at 100,000km but 170,000km so never worry again!!!

Your call. And not i cant answer your question sorry

[made_guy]

i think i've read if you were replacing or adjusting things like a cam gear, unless the belt is pretty 'fresh' you should replace it at the same time as taking it off and putting it back on is not good for its safety. i've got a spare brand new dayco one you can have for $50 if you want??

[ICER33]

done it, now it wont start!!!!!!!!!

what can i do, im positive the tiing marks line up

can anyone help please

[Jonny P Star]

Edited November 17, 2007 by Jonny P Star

[R338OY]

Some pics would be good for those who can't recognise parts.

Great write up though

[Birth]

To save some of the hassles with using a mirror to line up the timing mark on the belt with the crank gear you could use liquid paper or something to mark the side of the belt so that you can see which groove the mark is in.

[Torques]

Mark position of crank angle sensor on timing cover, undo the 3-set screws and remove crank angle sensor.

Alright ... I might be a bit late for this reply ...

But I was wondering why you have to mark the position of the crank angle sensor?

I checked the workshop manual and it did not mention any position marking necessary.

Can the sensor be adjusted? Or has it to be adjusted?

I'm asking because I want to remove the cover to check the timing belt.

Cheers,

Andreas

[heller44]

Just mark it to get it close to where it should be, you will have to adjust it with a timing light after you refit everything anyway, but then if you needed to be asking this you probably shouldn't be doing it either..

[Torques]

Just mark it to get it close to where it should be, you will have to adjust it with a timing light after you refit everything anyway, but then if you needed to be asking this you probably shouldn't be doing it either..

Thanks for the answer and no worries I am quite a good mechanic ..

I have the Skyline as a newer car, and am not familiar with all aspects of the engine.

I think it's only natural that you ask if there's anything unclear and removing the upper cover seems within my 'grasp' I guess

Cheers!

[gotRICE?]

Just mark it to get it close to where it should be, you will have to adjust it with a timing light after you refit everything anyway, but then if you needed to be asking this you probably shouldn't be doing it either..

You could say that if you need a 200step tutorial you shouldn't do it either tho, couldn't you?

[heller44]

torques - think of it more as just removing the distributor, same mechanical purpose.. I have an old v8 in my shed with a distributor mounted off the front of the camshaft same as a cas, not a new idea.

gotrice - possibly, but then it is up to the individual how keen they are.

[Torques]

torques - think of it more as just removing the distributor, same mechanical purpose.. I have an old v8 in my shed with a distributor mounted off the front of the camshaft same as a cas, not a new idea.

gotrice - possibly, but then it is up to the individual how keen they are.

Well, everybody is new at something sometimes ..

It's funny that the manual does not say that you have to adjust the timing after you removed and refitted the crank angle sensor.

However, there is an entry in the maintenance section that you can adjust the ignition timing using a timing light and by rotating the sensor.

In any case you pointed me in the right direction (thanks for that), so I will mark the position and probably double check the ignition timing since it's

so much fun working with a strobe light anyway

Cheers,

Andrew

Edited August 13, 2009 by Torques

[Joe Nash]

not sure if this applies but it seems pretty good

http://www.scribd.com/doc/16408415/How-to-GuideChanging-the-Timing-Belt-on-a-RB25DET

[Missileman]

I'm going to attempt my 1st TB change on Thursday, weather permitting as I have no garage. Went over to one of my mates to borrow some tools, he made his own puller tool as a teenager in metal shop at school some 49 years ago, am eager to give it try

[wiix]

hey im just curious how to hook up the timeing light can i use a standered one for a ht lead and modify it to work on a coil or not ?