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Cambelt change on a R33 GTS-t - by Bob Owen I struggled finding any information on the web, with detailed instructions for a cam belt change I did find the actual Nissan belt number however, so decided to change it myself. Total time needed, IF you have all the tools is around 3 hours. In reality, for most of us anyway, you will probably need nearer 5 or 6 hours. This covers the coffees, the fags, answering the phone, finding that dropped screw, locating that bloody 10mm spanner that was here a moment ago and all the other distractions that plague the home mechanic Before you decide to go ahead yourself,you do need all the normal metric spanners and sockets, including a 23mm one for the crank pulley bolt and allen keys, plus a persuader extension tube for the socket wrench. You will also need a suitable pulley extractor to remove the crank pulley, and ideally a torque wrench for re tightening. A bottle of Tippex is helpful to mark various timing marks, but any other suitable means of marking can be used You will, of course, also need the cambelt. While carrying out this job, it makes sense to replace all the ancillary drive belts that drive the alternator, air con and power steering. The Nissan numbers for all these are:- CAMBELT - 13028-20P25 (Supersedes 20P10) AIRCON - 11720-77A01 (Supersedes 77A00) ALTERNATOR - 11720-42L01 POWER STEER - 11950-58S01 If your local Nissan dealer can't or won't help, (Even if they do, they will probably have to order them in) then try Middlehurst Nissan parts on 01744 457166. They usually carry them in stock and will take orders over the phone. Cambelt is around 40 pounds, the rest are about 10/11 pounds each and overnight delivery around a tenner... My local dealer wouldn't even take cards over the phone, you would have to call in so they could swipe the card. Then call back to collect the parts, customer service eh? The job itself is mainly removing light parts, fixed by small nuts and bolts, the crank pulley being the only pig element. I will show you a rather neat way of locking it in place while you undo the main fixing bolt, with nothing more than a little nylon cord! (Thanks for that Roger) DISCLAIMER: If you have the tools, and some mechanical experience then this is not a particularly difficult job. Using this as a guide, you should find no major problems. This article is only MY experience and I do not accept ANY liability should you choose to go ahead. If you are in any doubt, seek qualified assistance. Any constructive comments or further detailed info that could be included are most welcome - Bob.owen@btinternet.com All references to LHS (Left Hand Side) and RHS (Right Hand Side) are with the viewer standing in front of the car facing the engine THE BEGINNING In an ideal world, with a keen conscience and plenty of time, you would obtain the correct locking tools, which would require starter motor removal, you would remove the radiator, to avoid any possible damage, you would drain all coolant, you would wheel out your 'Snap On' tool box, you would obtain the correct puller, in fact if your that keen, you'd probably pay someone else to do it! Anyway, here's how I did it. The rest is up to you! 1 - Reread disclaimer. Get the kettle on, make a nice brew, lift the bonnet and identify the various parts In front of you is the cambelt cover, located on the front of the block, upper right of the cambelt cover, is a round device fixed with 3 bolts. It has an electrical loom entering it. This is the cam sensor. On the LHS, notice the fan is held onto a pulley by 4 nuts. At the bottom of the cam belt cover (Which is actually in two parts, an upper and lower) you will see the main crank pulley with all the belts on These belts, 3 off, go to:- a) LHS the alternator and fan b) RHS upper the power steering pump (PSP) c) RHS lower the aircon compressor 2 - Finish your brew. Remove the spark plugs. Disconnect the battery. Remove the radiator OR find a suitable piece of cardboard to cover the radiator matrix with. You must protect this - the slightest touch on this WILL bend the fins and block your radiator air flow off or worse. Unscrew the clamp holding the top hose on the radiator LHS and pull off. You will lose a litre or so of coolant. Bend the hose back, out of the way. Undo the 4 nuts holding the fan stem on its pulley and gently remove 3 - Identify the plastic shroud fixed to the radiator rear. On the LHS is a sensor. Unplug this and remove the loom from the clips on the shroud. Tuck the loom and plug well out of the way. Remove the two top screws holding the plastic radiator shroud in place. Ease the shroud partially out and pull the hose that is clipped in the bottom of the shroud, out. Remove the shroud 4 - On the LHS identify the alternator locking bolt and adjuster screw SEE FIG.1, unslacken these, which allows the belt to come off the alternator. The power steering pump on the RHS has a similar arrangement, so repeat as per alternator
5 - If you examine the A/C compressor belt, you will see it passes an idle wheel near the bottom of the engine bay. To access the adjuster, you need to drop the plastic pan running across the engine bay bottom. Access is easy without crawling right under the car. Remove the front 3 bolts, then the middle 2. The tray will drop down at the front, being held up by the rear most bolts that do not need removal. Slacken the idler off 6 - Remove all ancillary belt THE PIG 1 - Having now cleared a space, so to speak, you can get on with the job of removing the crank pulley. This is held in place with a central bolt. You will need a 23mm socket and a good extension bar to undo the beast. The problem of course, is that the pulley turns with it. My motor is an auto, if you have a manual you may be able to put it in gear and get someone to stomp down on the brakes, allowing you to undo the bolt.... maybe I'm sure that Nissan will have some engine locking device, probably involving starter motor removal and locking the starter ring The solution I used is incredibly simple and easy. It works too! I took a length of nylon cord, about 1.5M long and about 4mm diameter. Military types will know this as 'para cord' 2 - Look at FIG.2, you need to wrap the cord around the pulley and pass it through itself as shown. Then it needs to pass over the alternator pulley. To adjust the length, twist the cord before putting it on the alternator pulley, which will effectively shorten it
3 - Now, using your extension shaft on the wrench and rotating anti clockwise, it should lock the crank pulley and allow the bolt to be undone. Once the bolt is removed, you now need the puller to pull the pulley off the crank. I used a cheapish 2 legged puller I've had knocking about, but needed to cut 50mm off the legs to allow it to fit in place, without fouling the radiator The pulley is actually a collection of pulleys fixed together via an internal rubber mount. This means that the rubber will compress as the pulley assembly is pulled off, so the puller has to be wound more than normal, to 'crack' it off the shaft. The pulley assembly is keyed onto the shaft Once removed, it is worth cleaning the shaft and pulley mating surfaces, to make life easier on replacement CHANGING THE BELT 1 - Having gotten this far, the worst is over. Make a celebratory brew. Locate the cam sensor on the upper RHS of the cam belt cover SEE FIG.3, this is held in place by 3 bolts which allow adjustment, as the fixing holes are slotted. Mark the cover and the sensor with Tippex or some other marker before removing. This needs to be replaced back in the exact same position! It is on a keyed spline and can only go on/off one way. Ease the sensor out, pull the wiring loom out of the clip and tuck it out of the way
2 - Remove the upper cam belt cover. They are held in place with bolts fixed in rubber grommets, don't lose these! They are also different lengths, so take note where each one comes from. Ease the cover off 3 - You should now see the cam belt in all its glory. You will see the two cam pulleys at the top, two rotating wheels in the centre and the bottom crank belt pulley. The RHS centre wheel is a fixed idler. The LHS centre wheel is the tensioner 4 - There are 3 timing marks you need to identify. Each cam pulley has a dimple alongside one tooth. Behind each cam pulley is a notch on the engine block. I marked the dimples, the back of the corresponding tooth and the block marker with Tippex SEE FIG.4 for LHS
The crank pulley you removed has a series of notches. Holding the pulley in the orientation it came off, the TDC (Top Dead Centre) notch that is the most anti clockwise one. On my car, this was marked with a dot of orange paint. On the lower cam belt cover is a raised marker on the upper RHS. Mark these with Tippex SEE FIG.5
5 - Ease the crank pulley back on, so it engages the keyway. Rotate the engine by hand, (Rotating the crank pulley) so that the crank pulley and the lower cover mark are in line. This places the engine at its TDC point. Observe the cam pulley marks as you rotate the crank pulley. You should see them in line with their block marks, when the crank pulley is at TDC. Remember the cam pulleys will pass their marks TWICE for every rotation of the crank. You must arrive at a point where all 3 marks are aligned. 6 - Remove the crank pulley again and the lower cam belt cover. The tensioner has an allen key hole off centre, which allows you to rotate it with an allen key and vary the tension. It is locked in position by a central nut. Slacken the nut, rotate the tensioner against its internal spring to its slack position. Lock it in this position and ease the cam belt off by edging it of each pulley in turn by a millimetre or so at a time. Check the idler wheel (RHS) is in good condition easy to move and has no wobble. If not, replace 7 -Fit the new belt on the pulleys, taking care to ensure there is no slack on the RHS. This is essential as even one tooth slack will screw the cam timing up and probably your engine! Note that the belt is marked to indicate its front edge. Release the tensioner and recheck all the timing marks. All 3 must be aligned. If not, then redo. The tensioner must be on and all 3 marks must align correct – that is, the crank pulley mark and each of the cams. Once correct, retighten the tensioner centre nut to lock it 8 - Ease the crank pulley on again, so it just catches the keyway, and rotate the engine at least 2 times. If any resistance is felt - STOP - you may have made a mistake with the timing and now have interference between piston and valve. Re check that all 3 timing marks (The crank and each cam) are perfectly aligned 9 - Make a brew. Its downhill from now on FINALLY 1 - Rotate the crank pulley AGAIN and recheck the marks are all perfectly aligned 2 - Re read the disclaimer at the top of this article. Rotate the crank pulley AGAIN and recheck the marks are all perfectly aligned!!!!! Remove crank pulley 3 - Refit the lower and upper cam belt covers, leaving the top one a little loose. Refit the crank pulley on the crank. Use the rope technique described earlier (Or your engine locking device) but in reverse. I tightened the crank bolt to 140 ft/lb which I remember from the last car I did. I don't know the Nissan figure – you may want to check this (140 ft/lb is fine - RonS), remove rope 4 - Refit cam sensor ensuring you re align with the marks made earlier, jiggling the still loose top cam belt cover to allow central fitting. When correct, retighten sensor and cover 5 - At this point, rotate the crank pulley a number of times to ensure the engine can turn OK and there are no strange noises. Refit plugs and reconnect battery 6 - Make brew. Give engine a good coat of 'looking at'. The engine can be started to check all is well. Make sure all loose items, looms, sensors are clear. Remember the water pump is not running – so there is no coolant circulating! Do not run for more than a minute 7 - Refit and tension all belts. Refit plastic lower engine pan. Refit fan and radiator shroud, ensuring sensor and bottom hose are fitted as they came off. Refit top hose and top system coolant up 8 - Clean and polish everything, check all parts are refitted, remove all tools and wonder where that screw that's left over came from. VROOM VROOM! (Info should be good for any RB engine, nice work Bob - RonS) |
