Mechanical engineering | Vehicles » Timing Belt Replacement, 1997 Isuzu 3.2V6 6VD1 SOHC Jackaroo

This document attempts to provide a photo journal of the timing belt replacement procedure on my 1997 Isuzu 3.2V6 6VD1 SOHC Jackaroo (it may also be generally applicable to other Isuzu V6 models) Isuzu and Holden recommended a 5 year/100K Km replacement schedule for the timing belt on my vehicle, which I have owned from new. I replaced the original belt at 5 years/70K Km - its condition was visually good. I did not replace the tensioner, idler or water pump at that time. At 10 years/150K Km I decided to replace the belt, hydraulic tensioner, tensioner pulley, idler pulley and water pump. The result: all of the old parts appeared to still be in good condition. I have the satisfaction of knowing that they have been replaced. Worst task (if replacing the water pump): scraping off the old gasket - take care with the alloy surfaces. NOTE: if the water pump is not replaced there will be no requirement to drain or refill the coolant.

------------------------------------------------------------------------------------------------------------------------------------DISCLAIMER: The parts, tools and procedures mentioned in this journal have worked fine for me and my vehicle but no guarantee is given nor responsibility accepted regarding their accuracy or appropriateness. You must make your own assessment of the task and refer to an appropriate workshop manual to check the procedures and torques mentioned and undertake the task AT YOUR OWN RISK. Read through the entire process before deciding to take it on yourself. Assess your own ability and experience. It took me about 75 hours - but Im fussy The Gates guide suggests 3.5 hours but I would hate to have a dealership apprentice rushed into doing mine in that time I will answer questions but do not wish to get into debates over alternative methods - if you have other ways of doing the job please feel free to publish them. However, if there are any factual errors or

omissions, I will be pleased to correct them. ------------------------------------------------------------------------------------------------------------------------------------ACKNOWLEDGEMENTS: Bolt torque specifications and diagrams came from Isuzu workshop manuals. ------------------------------------------------------------------------------------------------------------------------------------PARTS: Shopping around I got the following parts [pic 1]: Pic 1 Gates TCK221 Timing Belt Component Kit (belt, tensioner pulley, idler pulley) AC-Delco T43095 Hydraulic Timing Belt Tensioner from www.rockautocom (USA) for approx AU$320 including shipping (took about 3 weeks delivery due to delay in getting the tensioner). GMB WP3112 Water Pump and Gasket from my local Repco outlet $137. If you replace the water pump you will also need appropriate coolant. I collected and reused mine because it was only 12 months old and needed about 0.5litre top-up for spillage Dont buy cheap

pre-diluted stuff get approved specification coolant concentrate and mix 50/50 with demineralized or distilled water Also, I like to coat the new paper water-pump gasket with Permatex No.3 Aviation Sealer - but this is not specified by Isuzu. Alternatives: When I replaced the first timing belt, Holden supplied me with ‘genuine’ part GM8970163260 which was also manufactured by Gates. This time, while I had the tensioner and idle pulleys out, I recorded the bearing numbers: Tension pulley bearing NTN 6006LUAX which appeared to be removable with a press; Idle pulley bearing NSK 40BD48DWA which appeared integral with the pulley and perhaps not available as a separate bearing. ------------------------------------------------------------------------------------------------------------------------------------TOOLS: General DIY mechanic tools, including the following: Torque wrench (or calibrated wrist - I prefer the wrench for settings over 30lb-ft). 24mm (15/16AF) socket and short

extension bar for the crankshaft pulley bolt. Length of pipe to extend the torque wrench handle thus requiring less personal effort [pic 2]. Pic 2 Clamp/lever to hold the crankshaft pulley - there are various solutions for this - mine, which I had cut and drilled by my local steel supplier, is shown in the photo’s [pics 2 to 5 & 15]. The dimensions do not need to be precise and the holes simply need to be large enough to permit a 1/2inch socket extension bar to pass through loosely. The 2 bolts only need to match the existing threads in the face of the crankshaft pulley they will not be tightened - they just act as pins to stop the pulley rotating During installation I was able to restrain the crankshaft using 5th gear in the manual transmission, with the handbrake on - I don’t know if this will also work during removal. Pic 3 Pic 4 Pic 5 Socket sizes 10, 12, 13, 14 and 17mm (assorted socket lengths, extensions and swivels are useful). I favour 3/8inch drive

because they are generally more compact but I assume that 1/2inch drive will suffice. Ring and open-end 12mm spanner for the fan assembly [pic 10]. If NOT replacing the hydraulic tensioner: a bench-vice or large G-clamp or similar to retract the piston and a fine-gauge picture-hook nail or stiff fine-gauge wire to hold the retracted piston [pic 46]. 2 spring-loaded clothes pegs or similar clamps to hold the new belt during fitting [pic 43]. If replacing the water pump: gasket scrapers (old chisels etc.); large bowl/container to collect the coolant An old rear-view mirror or other small hand-held mirror is very useful to examine/find hidden bolts. ------------------------------------------------------------------------------------------------------------------------------------PHOTO NOTES: Some of the photo’s are used twice, first during the Removal phase and then during the Installation phase to illustrate the steps [eg. pics 35 & 45] Therefore, some parts like belts may not be

visible even though they would normally be present at the step being described. Refer to the text for the order of tasks. Please excuse the dusty condition of the engine bay - drought water restrictions prohibit cleaning motor vehicles! ------------------------------------------------------------------------------------------------------------------------------------REMOVAL: 1. Negative (ground) battery terminal - for safety reasons - the starter must be rendered inoperable while you are working on the engine. Later you will need to enter the radio/cassette security code if it has one 2. Isuzu suggest removal of the Air Cleaner Assembly but this was not necessary on my vehicle [pic 6] Pic 6 3. Isuzu suggest removal of the Radiator Lower Fan Shroud but this was not necessary on my vehicle 4. Radiator Upper Fan Shroud: 4 spring clips (2 each side) halfway down the sides clamp the upper and lower shrouds together. Twist the tip of a large flat-bladed screwdriver to prise them off

into your fingers 2 plastic retainers hold the top of the shroud to the radiator header tank - twist the phillips head and push the whole retainer out from the other end [pics 7 & 8]. Pic 7 Pic 8 5. Place a sheet of plywood or cardboard to protect the inside of the radiator core [pic 9] Pic 9 6. Cooling Fan Assembly - this is definitely done BEFORE removing the fan/alternator belt because the belt tension is needed to hold the fan pulley while undoing the 4 nuts [pic 10]. Pic 10 7. Power Steering Pump Drive Belt: the adjuster lock bolt is very visible but the 14mm pivot bolt is accessed through a hole in the face of the pump pulley [pic 11]. It may be necessary to place the transmission in NEUTRAL and turn the motor CLOCKWISE from your viewpoint using the 24mm (15/16AF) crankshaft bolt and torque wrench to align the hole and bolt. The bolt only needs to be loosened enough to permit the pump to swivel to permit removal of the belt. Pic 11 8. Air/Cond Pump Drive

Belt - loosen the large nut on the adjusting pulley and then unscrew the long, small 10mm adjusting bolt to release the belt tension - the adjusting pulley can be partially seen just to the right of the fan assembly and left of the A/C pulley in [pic 10]. 9. Splash Guard from underneath the front of the vehicle [pic 12] Pic 12 10. Alternator/Fan Drive Belt - loosen the alternator pivot bolt (above the alternator and just below the power steering pump mounting bracket - a small mirror is handy to find it). From under the front of the vehicle loosen the alternator adjuster clamping bolt and unwind the long adjusting bolt to release the belt. 11. Fan Pulley Assembly - 2 nuts and 1 bolt [pics 13 & 14] Pic 13 Pic 14 12. (no step - numbering error - coffee break perhaps?!) 13. Crankshaft Pulley - using some method of holding the crankshaft while undoing the 24mm (15/16AF) bolt [pics 15 to 18]. My clamp uses a couple of bolts hand-tightened into the existing bolt-holes in the

face of the pulley, and it rests against the power steering pump bolt for leverage. Alternatively, with a manual transmission, it may be possible to hold the motor in 5th gear and handbrake on. You may need to research other methods. After the bolt tension has been ‘cracked’ it easily unscrews and the pulley can be pulled off by hand - I used a soft-faced hammer to tap the sides to give it some friendly persuasion to overcome the mild corrosion holding it [pics 19]. Pic 15 Pic 16 Pic 17 Pic 18 Pic 19 14. Coolant - ONLY if you intend to replace the water pump - I used the plastic butterfly drain plug on the bottom radiator tank near the bottom hose and the oil-cooler water hose (shown with a white arrow) [pics 20 to 23]. If you discover later that you will have to replace the water pump you can, of course, drain the coolant at that time. Pic 20 Pic 21 Pic 22 Pic 23 15. Oil Cooler Hose Bracket Mounting Bolts - 2 bolts with spacer tubes behind -

both shown with sockets attached in [pic 24]. Pic 24 -------------------------------------------------------------------------------------------------------------------------------Note: the plastic timing covers contain steel spacers in the bolt holes - ensure that they don’t fall out while removing the covers - or if they do, find and reinsert them. All three covers are shown in [pic 28] 16. Right Bank Timing Cover - (on your left looking at the engine from the radiator end) To permit removal of the plastic cover I found it necessary to slightly loosen the 24mm (15/16AF) power steering pressure hose union, rotate the union to allow the pump to swing to the left as far as possible and then temporarily re-pinch the union to prevent fluid leakage [pics 25 & 26]. Pic 25 Pic 26 17. Left Bank Timing Cover - (on your right) [pic 27] Pic 27 18. Lower Timing Cover - all three covers shown in [pic 28] Pic 28

-------------------------------------------------------------------------------------------------------------------------------!!!WARNING!!! DO NOT get excited and be tempted to whip out the belt yet - the exposed timing belt is shown in [pic 29]. Pic 29 19. Align The Timing Marks Replace the crankshaft pulley bolt into the end of the crankshaft ( I used an old bearing spacer to reduce the number of threads) [pic 30]. Pic 30 Ensure that the transmission is in NEUTRAL. Use the torque wrench to rotate the crankshaft in a CLOCKWISE direction from your viewpoint until the camshaft timing marks and the crankshaft timing marks are aligned (take it slowly to let the compressions subside): Each of the CAMSHAFT pulleys has a notch on the front outer perimeter which aligns with a ‘pimple’ on the metal plate behind each pulley [pics 31 & 31A]. Pic 31 Pic 31A The mark on the front perimeter of the CRANKSHAFT pulley should be at 9 o’clock and directly opposite it on the

other side of the pulley at 3 o’clock is a notch at the rear edge of the pulley which aligns with a groove on the face of the oil pump housing (which is immediately behind the pulley) [pics 32 & 32A]. Pic 32 Pic 32A When all marks have been aligned correctly you may also see the original timing belt marks aligned. Don’t fret if you don‘t - it doesn’t matter - what is important at this stage is that the moving pulley marks are correctly aligned with the static marks on the parts behind them. If you really must you can examine the belt, and if you can see marks on it, rotate the crankshaft clockwise until the belt marks coincide with the pulley marks - then double check that the static marks are still aligned. !!!WARNING!!! DO NOT rotate the crankshaft after the marks have been aligned - we need to keep this position until the new belt has been installed. 20. Hydraulic Tensioner (or pusher) - remove the 2 bolts - the tension isn’t very strong so nothing is going to

fly-off [pics 33 & 34]. Pic 33 Pic 34 If you intend to re-use or to store the old hydraulic tensioner - use a bench vice or other tool to compress the piston back into the cylinder housing until you can insert an appropriate retaining pin through the aligned holes in the housing and the piston. Then stand the tensioner vertically on the base of the housing, with the piston uppermost. 21. Tension Pulley - even if you do not intend to replace it - remove the pivot bolt not the bearing bolt [pic 35] (the belt is not shown). Pic 35 22. Idle Pulley - even if you do not intend to replace it [pic 36] Pic 36 23. Timing Belt 24. Water Pump - ONLY if you intend to replace it [pic 37] - if not, check for leaks and for roughness in the bearing - it’s your call if you don’t mind repeating the job to replace the pump at another time, should it fail. Pic 37 After 10 years using specification coolant you can see the condition of my original pump compared with the new one

[pic 38]. The bearing felt OK but not as smooth as new Pic 38 The removed timing belt and its components in their relative positions are shown in [pic 39]. Pic 39 ------------------------------------------------------------------------------------------------------------------------------------INSTALLATION: NOTE: clean all bolt threads with a wire brush. 1. Water Pump - if it was removed Carefully clean the alloy gasket mating surfaces [pic 40]. This is a fiddly and time consuming task persevere and check ALL around the surfaces Pic 40 I then lightly coated the new pump mating surface with Permatex No.3, placed the new gasket over it and then lightly coated the other side of the gasket - but this is not specified by Isuzu. NOTE [pic 41A]: bolt no.7 is long and double double-ended, the incorporated flange is used to retain the pump and the incorporated nut is installed away from the pump. The extended end thread will later retain the lower plastic timing cover. NOTE [pic

41A]: bolt no.11 will not be fitted until later when the fan pulley is installed Pic 41 Pic 41A Fit the pump keeping the gasket in place by loosely inserting some bolts [pics 41 & 41A]. Double-check that the gasket is in place and then progressively (doing multiple passes around the bolts) tighten to 13 lb-ft (this is firm not tight) in the specified order [pic 41A]. There will not be a bolt at no11 2. Timing Belt This task is made easy because both the tensioner and idle pulleys were removed earlier. I previously did it the workshop manual way and it was a pain. By using this method there will be no need to move the crankshaft or struggle with the belt during installation. NOTE: the printed numbers/lettering on the belt should be readable from where you are in front of the engine. Locate the dotted-line timing mark printed on the new belt, line it up approximately with the mark on the crankshaft pulley. Locate the other 2 timing mark lines printed on the belt and

approximately line them up with the marks on each camshaft pulley. Loosely place the belt under the crankshaft pulley, over the camshaft pulleys and under the water pump pulley. Check the belt path and ensure that it is not snagged. Align the dotted-line timing mark on the belt with the mark on the crankshaft pulley [pic 42]. Pic 42 Align the timing mark line printed on the belt with the right-bank (on your left) camshaft pulley mark, smooth the belt into the pulley teeth and hold in place with a clothes peg or similar [pic 43]. Pic 43 Evenly pull the belt from your right-hand side of the water-pump pulley, up over the left-bank (on your right) camshaft pulley and align the timing mark line printed on the belt with the camshaft pulley mark. Smooth the belt into the pulley teeth and hold it in place with another clothes peg. Double-check all of the timing marks and the belt path. 3. Idle Pulley to your right of the water pump and on the outside (smooth side) of the belt and

tighten the bolt to 31 lb-ft [pic 44]. Pic 44 4. Tensioner Pulley to your left of the water pump and on the outside (smooth side) of the belt and tighten the bolt to 31 lb-ft [pic 45]. Pic 45 (The earlier Isuzu workshop manual 1992~ discusses an adjusting bolt on the tensioner pulley bearing but it does not exist on the parts for my vehicle). 5. Hydraulic Tensioner (pusher) below the tensioner pulley fulcrum and tighten the 2 bolts to 14 lb-ft Then remove the pin used to retain the piston [pic 46]. Pic 46 6. Remove the clothes pegs from the camshaft pulleys FINAL CHECK ALL OF THE TIMING MARKS AND THE BELT PATH. You can put the transmission in NEUTRAL and turn the crankshaft in a CLOCKWISE direction to check the belt movement now if you wish. 7. Remove the crankshaft bolt - if you have a manual transmission put it in 5th gear and apply the parking brake. In any case a sharp jerk on the torque wrench should budge the bolt [pic 42] 8. Lower Timing Cover, Left-Bank Cover (your

right) then Right-Bank Cover (your left) - all shown in [pic 47]. Ensure that the steel spacers remain in place in the plastic covers and tighten bolts/nuts to 12 lb-ft Pic 47 9. Oil Cooler Hose Bracket Mounting Bolts - 2 bolts with spacer tubes behind - tighten to 16 lb-ft - both shown with sockets attached in [pic 48]. Pic 48 10. Oil Cooler Water Hose - if it was disconnected (shown with a white arrow) [pic 49] Pic 49 CLOSE ANY OTHER coolant outlet(s) if they were opened. 11. Crankshaft Pulley Clean any corrosion from the end of the crankshaft and inside the pulley and lightly oil them [pics 49 & 50]. Pic 50 Align the key on the crankshaft with the groove in the pulley and push the pulley onto the shaft. Restrain the crankshaft by your favoured method. Torque the bolt to 123 lb-ft. 12. Fan Pulley Assembly - tighten nuts and bolt to 16 lb-ft [pic 51] Pic 51 13. Alternator/Fan Drive Belt - place the belt over the the fan pulley, crankshaft pulley and alternator

pulley - note that it cannot be adjusted until the fan assembly is installed later. 14. Air/Cond Pump Drive Belt - fit and adjust the belt - the belt on mine was so tight that I found it easier to remove the adjusting pulley, install the belt and then replace the pulley. 15. Power Steering Pump Pressure Hose - restore to its normal position - loosen the 24mm (15/16AF) hose union, rotate the union and allow the pump to swing back to the right and then re-tighten the union [pic 52]. Pic 52 16. Power Steering Pump Drive Belt - place a 14mm socket onto the pivot bolt through a hole in the face of the pump pulley to hold the pulley in place while the belt is fitted [pic 53]. Fit and adjust the belt - there is a 1/2inch square hole punched into the top of the pump mount which is used to lever the pump with a torque wrench (or similar) to tension the belt - then tighten the adjuster slot lock bolt and the pivot bolt. Remove the socket from the pivot bolt, which may need a pull on the belt

or a slight turn of the crankshaft if the pump pulley is gripping the socket. Pic 53 17. Cooling Fan Assembly - install and evenly tighten the 4 nuts [pic 54] - even if you cannot tighten them fully perform the next 2 steps when they have been evenly tightened as much as possible. Pic 54 18. REMOVE THE SHEET OF PLYWOOD OR CARDBOARD which was placed to protect the inside of the radiator core [pic 55]. Pic 55 19. Alternator/Fan Drive Belt - under the front of the vehicle tighten the long adjusting bolt to tension the belt - tighten the adjuster clamping bolt. Back in the engine bay tighten the pivot bolt (above the alternator and just below the power steering pump mounting bracket). If you were previously unable to fully tighten the fan assembly nuts you can complete that now because the belt will be restraining the fan pulley. 20. Splash Guard underneath the front of the vehicle [pic 56] Pic 56 21. Radiator Upper Fan Shroud - (you did remove the sheet of plywood used to

protect the radiator core didn’t you?) - hand press the 4 spring clips (2 each side) halfway down the sides to clamp the upper and lower shrouds together. Push the 2 plastic retainers in by hand which hold the top of the shroud to the radiator header tank [pic 57]. Pic 57 22. Coolant - ONLY if it was drained - ensure that all outlets have been closed I re-used my coolant so I filtered it through a couple of layers of pantihose fabric placed over a funnel to remove any debris that may have fallen into the catchment container. I also turned the heater to full hot to help bleed the system Top up as necessary later after the vehicle has been run [pic 58]. Pic 58 23. Negative (ground) battery terminal - you will need to enter the radio/cassette security code if it has one. ------------------------------------------------------------------------------------------------------------------------------------CONCLUSION: Check the engine bay for stray tools and equipment - no socket

left on the crankshaft bolt etc. Check that the transmission is in neutral (or park if auto) and test-fire the engine. The ECM may take a while to adjust because the battery was disconnected. Test drive the vehicle and, after cooling off, re-check the coolant level if it was drained