I have a 1988 TN and I have to take the head off to replace the gaskets and wanted to do it myself to save $350. How hard is the task and what do i watch out for. I am a bit worried about the timing chain. Hopefully someone has done it. Thanx

It's not hard at all... it should be easier for you too since you have a carby. Most gasket kits have a diagram showing you which order the bolts should be done up when you get the new gaskets in there. The only advice I can give you about the timing chain is to stop it from falling in to the sump... just tie it up with wire or something. Best option is to get yourself the Haynes or Gregory's Manual and follow that. You don't have to spend $350.

well, i believe myself to be some sort of an expert when taking the head off the 1st gens. i did it 3 times in 1 month so i know wat to do. i put the head back on in 20 mins and had every nut and bolt tightened up thats how efficient i got at it lol... get ur gaskets and some water resistant gasket goo. u can get it from supercheap.

ok... well first u have to take the airbox assembly off (carby). this is pretty easy so i wont write about it.

drop all ur coolant. undo the drain plug on the radiator and get rid of it all. trust me.

now, undo all the nuts holding the intake and exhaust manifolds on. dont let the exhaust manifold rest against the radiator. if u have to, least put a rag so it dosent put a hole in it.

next, undo the water pump pully. there is one bolt. unscrew this and wiggle the water pump pully off.

now, take off the rocker cover. there are 2 bolts on top. also, there is a pipe that connects to the rocker cover. a breather, this just pops off. (its on the right hand side as u look at it from the front)

ok, now take the little half-moon shaped plastic piece out of the head (on the right side once the rocker cover is off). take the rotor out (dizzy) and unscrew the bolt u c connecting the timing chain sprocket to the camshaft. there is 1 bolt, then a small piece with teeth that connected up to the rotor and then the sprocket. slide the sprocket off and sit it there. it cant fall through the head into the sump.

now, loosen all the head bolts. dont take 1 out fully then take another out. loosen them all.

this is the MOST important part. take ONE headbolt out at a time and LABEL which one it is. (it helps to draw a diagram of the head and number each headbolt 1-10. then on the diagram label where each headbolt (1-10) went)

u may need 2 ppl for this. after all the headbolts are out, carefully wiggle the head around to loosen the gasket. then pull upwards. get someone to hold the timing chain sprocket cause it WILL fall through the block with no head there. once the head is off and the timing chain sprocket is still there (pray), put a screwdriver or something through the middle of the socket.

CLEAN THE HEAD! scrape wats left of the old gasket off the block AND the head AND the manifolds. do NOT get aggressive thinking u can complete it quicker. it takes time and if u cut into the block and/or head, u could have serious troubles with the new gasket leaking etc. use a small blade (sharper the better) and come in at a MILD angle. go slowly, it will b worth it. if u are going to take the head off for a LONG time (a few days) then smear oil on the top of the block so it does not start to rust. if the head is only gunna b off for a few hours or less, dont worry about this. after scraping the head and block, get some metho and rub the top of the block and bottom of the head to fully clean the surface.

wen u put the head back on, put the labelled head bolts back into the places u took them from. (because the wear marks from the bolts are exactly the same and will settle back to their original position) tighten the head bolts to spec. (50nm, 80nm, 98nm) and in the correct way. (middle 2, then zig zag outwards from there.) this is where that gasket goo comes in handy, wen the intake manifold gasket is on, smear a nice amount of gasket goo around the water jackets. (the rectangular things on the manifold). make sure there is enough all the way around the water jacket.

wen putting the timing chain sprocket back on, there will b a small hole in it. make sure this is pointing directly upwards. this is TDC (top dead centre). and you will need it to start he car lol

ummm... then replace everything u have taken off. make sure the intake and exhaust manifold are done up tight. once everything is back 2gether (and that BREATHER hose is ON) try and start the car. (dont put the air box assembly on just yet, incase u have to redo something). once u can start the car, turn it off straight away. PUT IN SOME COOLANT. make sure the coolant hoses are done up properly (double make sure, u dont want leaks) and put in the drain plug. pour in just straight water. forget the nice green stuff for now...

get the car running and idle it for 10 mins. (if the car isnt starting, check the breather hose is on and muck around with the timing. (rotor) if the car backfires through the carby, its too advanced obviously. try and put it directly in the middle. youll know wat i mean wen u muck around with it. keep checking for water leaks and make sure the manifolds are done up properly. once 10 mins is up and/or ur happy there are no leaks. turn it off and leave it until the car is stone cold. not an ounce of warmth in the engine. once its cold, take the rocker cover off and retention the head bolts to 98nm. replace the rocker cover and start the car and idle for 10 mins. make sure there are NO water leaks. look everywhere. at every hoses end etc. put the airbox assembly back on and make sure everything is running properly. double check it all. look for water leaks again. keep the straight water in it til u retension the head in another 300km. go for a drive and DONT smash the car around. dont even take it past 3000rpm if u dont have to. (obviously if u need to floor it to get outta the way of a semi trailer, do it will ya?)

300km later - retension the head to 98nm. add in ur nice green anti-freeze stuff into the water. idle it for awhile to let it mix around. and everything is good.

hope this helps, sorry for the long post

Thanx fellas. That will be a huge help to me and me back pocket. Just wondering why you had to do it three times in one month..

...if the car backfires through the carby, its too advanced obviously. try and put it directly in the middle.

actually if it backfires the timing is too retarded... it pings when its too advanced :confused: :)

actually if it backfires the timing is too retarded... it pings when its too advanced :confused: :)

lol one or the other. keep it in the middle and u cant go wrong

get someone to hold the timing chain sprocket cause it WILL fall through the block with no head there.

both my gen 2 astrons have a plate under the cam drive sprocket that holds the sprocket up when it's off the cam. Obviously your's doesn't have this, does it have two 6mm threaded holes in the top of the block for this plate?

LLama, TM-SE-RED kept pulling his engine apart because he didn't realise that his engine block was cracked through the deck. :badgrin:

both my gen 2 astrons have a plate under the cam drive sprocket that holds the sprocket up when it's off the cam. Obviously your's doesn't have this, does it have two 6mm threaded holes in the top of the block for this plate?

LLama, TM-SE-RED kept pulling his engine apart because he didn't realise that his engine block was cracked through the deck. :badgrin:


we took the plate off cause it was unsightly. just looked like a bent chunk of metal. weight reduction too :bowrofl: . it dosent really matter that i took it off. not my problem now, im gettin a new engine lol