thats why i use the 20w50 only in the warmer summer months... acts like 20w cold and when up to temp acts like 50w

same with the winter blend... acts like 10w cold but goes to 30w when warm...

as for the transmission you can use 10w30 engine oil in it and it will help shift better...

when I got my truck at 79,000 miles the trans felt gritty and the shifts were gritty and it (still) will not go into 2nd gear when its cold with the clutch.

When I filled mine I just used the ATF as suggested and it was still gritty... so I flushed it and tried again and that didnt help.... I eneded up draining it and adding a quart of red lucas and a half quart of 80-90w and mixing those in a bucket with tranny fluid (2 quarts) and filling my tranny with that mix... it shifts smooth as silk and has the last 4 years but I still have the 2nd gear issue

 

Just an update, I have driven the truck about 350 miles and the noise has not got worse... nor better... still cant put my finger on it. Exhaust/AIR leak? Quite possible. I had myself convinced last night as I was driving down my road thats what it was, but then as I listened more, just not sure. Dont have a LOT of time as the noise slowly goes away. This morning I started it, still making the noise of course (was hoping someone came and fixed it in the night) I put it in 2nd gear, held the brake, slowly let out on the clutch to drag the engine down (wish I had taken a vid) no change in noise except it mirrors engine speed. Funny thing is, when if first starts, high idle at 1500rpm, doesnt matter if I tap the throttle and make it idle down, or leave it at high idle.. during high idle it makes no notable knocking/tapping sound, its not until it idles down and then the noise settles in which seems odd. I think I am going to run it a few hundred miles and send my oil in for analysis. I have never done this before, so not sure where in central Iowa does this.. up at Iowa State Im sure if nothing else.. or how much they need? Filter? etc... Need to find out if I have any issue i need to worry about... shouldnt be driving it or what. Thinking of doing a total restore this winter which may include rebuilding the engine, or getting a new engine, although I would really like to keep the engine with the truck. What would be the most cost effective way to go, IF there is a reason for a rebuild? Also, how difficult would it be to get another 100-150hp out of it? AND, would the standard manual transmission, which is my understanding is not that tough of a tranny, hold up to that much more power? Options? Even with an engine rebuild, for me, in Central Iowa, I think the hardest part will be finding me a rust free box. Darn near impossible around here. May have to road trip on that one.

 

Beings you say it doesnt happen right when you start it and then it does I may be inclined to think its in the AIR system part... you might try unhooking the vacuum to the AIR Divertor valve and see if you can hear it switch and then reproduce the knock/leak...

I'm still not convinced this is an internal issue

 

Man, Im not either! Where is the vac line? I called around today, can get an oil analysis for $12... a C2? Also called my mechanic I use if I either dont want to do a job, or cant figure it out. I can drop it off sometime next week, leave it overnight so they can take a listen first thing in the morning. He thought it may be the AIR also, said that is very common. I got a light and mirror out, from what I can see all is intact and it just doesnt quite sound like its coming from there. I still just cant pinpoint it. Get under the truck, and it sounds like its almost even coming from the clutch area, get on top, and now it seems to be coming from drivers top side. Very frustrating. But yes, it does not knock at all for a few seconds during cold start until it idles down. If I pull the vac line should it stop?

 

Also, to me, it sounds like the sound mine is making is half of the rpm? would this make sense for some type of exhaust or AIR leak? At least thats what it seems to me.

 

I keep having different things go through my mind. Would it tell me anything, as far as the AIR system, if I were to take the serpentine belt off and run it bit?

 

So as soon as it starts it quiet then a few seconds later it's a fairly loud knock until its warm. Guess I'll follow this thread again as that's exactly what mine does, does it in the morning, then I noticed lately it will when I leave work around 6-7 that night.

 

Yeah, not a real loud knock... not like some of the video I have watched on youtube, and putting load on the engine seems to make no difference. zero noise at first startup which I find very strange, as soon as it idles down, then it starts up. I can leave it at high idle and it remains quiet till it idles down, and its not because i just cant hear it because of fan noise or exhaust (although it may be exhaust or something) I had it in an enclosed shop, so I could hear everything as i started it.. have noticed it outside as well. only when it idles down, then the odd sound starts up until it gets warmed up, and it goes away, undetectable. Has me boggled. Is it possible for the oil pump to make any knocking noise if it were going out? I havent installed an actual gauge yet. This is driving me nuts.

 

Sounds like my problem, give it light throttle and it's gone, as soon as its idled down the knock is back, and mines fairly loud in the cab. I've never heard it outside as my truck would roll away ( no parking brake cable atm)

 

Hmmm, opposite here.. cant really hear it in the cab. I have a video posted earlier in this post if you want to compare.