95yoda22re

Just purchased the 261c camshaft from ted. I planning on installing it this weekend but need to know if i have to take the front engine cover off to loosen the tension off the timing chain because i am not sure if i cam just pull off the timing gear on the top and slide it back on.

xxxtreme22r

you don't have to, just zip tie the sprocket to the chain and lay it on the head. Just be careful not to spin it when you take it off. However, taking the cover off makes it easier to put back on. Should be somewhat easy if it's the original chain though that has already been stretched a little. It can be a real PITA to put one on with a new chain and whatnot with the cover already on.

before you start make sure the engine is TDC on the compression stroke and not the exhaust stroke. You can check this before you take the rocker shafts off by checking to be sure the #1 valves are loose.

1 piece of advice when you putt he rocker shafts back on to re-torque the head bolts that ALL of the rocker arms have been loosened, if they are not, it will skew the torque readings because the rockers will be pushing down on the cam lobes if that make sense.

P.S. Are you changing the cam with the head in place? If so you might want to take a ratchet tie down strap to hold the head in place before you take the head bolts out. Also clean the head bolt holes out with carb cleaner and a long pipe cleaner. Some of the head bolts might be tough to pull out as well because of carbon build up from the oil on them. I can't remember off hand which ones will be tight coming out. If you are taking the head off, you might as well just remove the timing cover. If you are removing the timing cover, you might as well replace the chain etc etc.

95yoda22re

the truck just had the timing chain and gears and water pump replaced. i plan on leaving the head on the truck. i didnt want to take the cover off either i just wanted to take the valve cover off and change out the cam shaft, is there any way to loosen the tension on the chain without removing the cover? if i have to take the timing cover off what else has to be removed?

95yoda22re

thanks im gonna give it a try this weekend, would you happen to know torque specs for the cam shaft

95yoda22re

ok thanks again

95yoda22re

ok so i still havent gotten time to put my camshaft in I just realized that all th ehead bolts have to come off when you were talking i figured like 2 held it in place. will i have to get my head resurfaced. The head gasket was fine before.

Pool Playen Bob

^^ get a flat edge something straight and a feeler gauge. and see if she's warped. that'll tell you if you should be concerned about it or not.

95yoda22re

that is a good idea but what kinda straight edge can I use that wouldn't be out .002 or .001 over the whole length?

Pool Playen Bob

a long ruler. a square.i cant think of that "t" thing for drawing.

sam333

You have to use a machinist straight edge( about $50) other wise its a waste of time(a ruler is not true enough) . Or take it to a auto machine shop and have them measure it for you.

Philbert

iTrader: (2)

I always wondered this - seen photos of the sprocket zip tied, with the head off. Even LCE has photos of engines for sale, sans head, with the chain and sprocket sticking out of the top of the timing cover!

I have to think that the crank sprocket would not maintain proper contact with the chain, and it would fall out? How does the tension remain on the sprocket???

TinMan

Phil, the inside of the TC has a little lip that goes around the bottom of the crank sprocket gear and does not let the chain fall down enough to skip a tooth. I have write ups where they just drop the chain down in the cover, because it will not actually come off the crank sprocket enough to cause a problem. I don't trust that though and leave the gear on the chain.

Philbert

iTrader: (2)

Holy cow - who knew!

That's good to hear. And funny too, since when I did my timing cover job (part 2) this year, my idle was terrible after the job and the truck kept dying after a minute. I thought I'd skipped a tooth down below and was dreading having to take the cover off a third time (I knew I'd lined it up right - this was when I was putting the "hidden bold" back on and slipped the cam gear off). Turned out that my distributor drive gear was off a tooth and that fixed it

This is really great to know now - thanks!

Now if only someone had a detailed DIY post on installing a camshaft.....

TinMan

Installing a cam is pretty straight forward. There is only one right way to do it. Take the head off remove rockers remove old cam lube new cam torque to specs reinstal head and rockers. Sorry fir the run on as i am on my phone. Later

Philbert

iTrader: (2)

I know - sounds simple - but like all these things on old trucks, they are not.

A guide with photos (like what 92 TOY did for his job) to help noobs out would really be great. Things people may not think about like:
- the clamping the head and block together with a tie down when removing head bolts, so that the head doesn't separate
- what kind of lube to use (lithium grease, motor oil?) when getting the head ready
- Having the engine at TRUE TDC (compression versus exhaust stroke and how to tell by jiggling the valves)
- Making sure the valvetrain is loosened before putting back on to avoid unnecessary tension and incorrect torque numbers
- securing the timing chain/sprocket if not removing the head
- are there journal bearings that need special treatment/do they need to stay with the same journals they came from?
- Cam break in procedure, valve adjustment


Basically a soup to nuts guide with photos, warnings, tips and tricks. Given how cheap cams are, I think it would really encourage a lot of folks on the fence about it due to the unknowns of the procedure - like what the ENGNBLDR FEK has become - there are great Timing Chain DIYs out there that I and several have used. And guides like 92 TOYs are a great example of a Yotatecher taking the initiative to save others headaches in the future.

I can't tell you how far I've come in the last 2 years just by reading and participating on YT (I'm still relatively a noob, but have made great strides and gained confidence in these jobs using the DIYs and guidance of members here). I know we can get tidbits here and there with threads like these, but I think many here would appreciate it if one of the veterans were to put together a comprehensive DIY that we could sticky

/off soapbox

95yoda22re

I do have my block one in machining i think i might take a run out to the college and mill a piec of stock and then surface grind it to make a straight edge. there is just something about ratchet strapping the head down i dont like lol

i will be just taking it right off and do a head gasket at the same time.