SOHC Chain Guide Question

[gniknave]

...and I did search, and got over 4 pages of results, yet didn't find an answer.

90 240sx base model 116,xxx miles. Just bought at 115k. Replaced plugs & wires immediately (ngk). Also changed oil.

On to the question. I've been reading about the timing chain issues on these things (ran into em while reading on my Q's chain guide stuff), and I see all this stuff about the upper guide on the dohc KA that is useless and you can just remove.

Does this apply to the sohc also? I don't have any noises or indication that there's a problem, but I'd rather nip it in the bud now and save myself the stress and money in the long run.

[DAEDALUS]

Your sohc has an upper guide?

[gniknave]

From the Chilton guide it appears not, but I'm wondering if a similar procedure can be done on the sohc, or if you need to replace the guides like in the Q. And also are there updated guides for these (metal backed)? Or is there just new plastic ones available?

Bare with me, I'm slowly learning this car.

[DAEDALUS]

Maybe better to ask Chris in NOM about the guides. An all-nylon guide is fine if it's beefy enough--note that the Q's replacement guide is all nylon on 1 side, but maybe 1" thick, vs the ~3/8"-wall original. As far as the upper guide I don't see a reason to have one. There's no straight length of chain up there, it goes right around the sprocket. If you find one up there post back--I'd be curious to find out why.

[180fan]

There is no upper guide. You just have the slack and tension side guides. The new ones are indeed metal backed for both the tension and slack side. The original design was metal backed tension side, but all plastic for the slack side.

It is MUCH easier to do a SOHC chain than a DOHC chain job. Reason, you don't have to drop the oil pan to do a SOHC timing chain job. Just pop the drain the oil and coolant, pull off the water pump first, then pull the distributor and the oil pump. They oppose each other and go through the same axis of rotation, you can't miss the oil pump (kinda looks like a goiter on the 24E), then pull the front cover (otherwise you'll get a crap load of coolant in your oil pan which isn't good either), you'll then see two guides, your chain, a three allen bolts, two o-ring-like things that have metal around it (goes between front cover and block with one looking like a flattened donut and the other has it's hole offset from the center), and be sure to match the links( with all the keyways (on the crank and the cam sprocket) pointed up) with the punchmarks on the sprocket that's at the crank and at the cam. Reverse for reassembly. Only pita is getting the oil pump and the distributor lined up again.

[SMoKeM240]

the one on the right is the one that breaks and rattles

[SMoKeM240]

because stock, they are all plastic, i got new upgraded metal ones from nissan

[DAEDALUS]

Spiffy! I love shiny naked engines.

[wild_maxx]

when u say silver link lined up with dot at 3 o'clock is the dot at 9o'clock position directly across from silver link?

[wild_maxx]

bump for an answer

[wild_maxx]

is this what i am supposed to line the silver link up with straight across from the dot?