My td8g has 2 year old with about 25 hours on it remand cummins 4bt engine in it. I’ve came to the conclusion that either the cam gear has came loose or the cam shaft is broken. What exactly holds the cam gear on, is it possible that it’s just loose on the cam end or do you think the shaft is broke. If it’s just the gear loose how would I go about putting everything back in time?
Likely a timing cover bolt came loose and got in the gears. Pull the injection pump gear cover and you may see the problem. Bob
I don’t know, I’m not the greatest diesel mechanic. If it’s a timing cover bolt wouldn’t it have the gears locked up? It’ll crank over & as far as I can tell all the gears are turning. But I took the lift pump off & the cam shaft isn’t turning. Like I said I’m not a professional just kinda learning as I go here. Thanks
Look up killer dowel pin. Might give you some ideas.
The pump gear cover takes 10 minutes to take off
Had a recon 4 BT 3.9 that broke the cam about half way back. Not sure how many hours but it does happen.
Mike What exactly are you calling the pump gear cover? Is the cover below the injection pump has 2 bolts that hold it on? If so I took it off really can’t tell much about it by looking & trying to put my finger in there. But like I said something is definitely not right because I know the cam isn’t turning but the gears seem to be. I’m going to start ASAP to take the front timing cover off. It maybe some time though because I go in for knee surgery in the morning.
Gear cover is in line with the injection pump on the front cover. Round and it just unscrews like a lid on a jar.
10-4 I know what you’re talking about now. Lol can’t believe I never thought of trying to take that off. Thanks for the help guys.
Still can’t hardly get around due to knee surgery but I managed to go take the front timing cover off the engine. It’s official the cam shaft is broke probably around the 1st lobe or so, not far in the engine. I looked & didn’t see the killer dowel pin so that’s probably the culprit. Also there was a what looked to be a retainer right behind the front end of the cam that was broke it had 2 bolt holes in it like it held the cam in place. Do you think it caused any more internal damage. What is the purpose for the kdp other than to cause problems. Do you think it’d be possible just to replace the kdp & camshaft with no other problems or is this 2 year old new engine set up for failure.
Unless you have the special cam tooling you have to pull the motor and turn it upside down to change the cam and lifters . Bob
That sure seems like a lot to pull the cam. I figured there was some other way to get the lifters out other than turning the engine upside down. When something like this happens is it more than likely to have other damage other than just the broken camshaft?
Can you see any sighs of damage to the timing gears ? If something went through them the pan needs to come off anyway. Why lead up to the cam getting broke? Bob
I'm not sure what yuu mean. You can raise the lifters with a magnet stick and suspend them with a zip tie. Then the cam and gear come out
Bob, I don’t see any damage to the gears they all look good. I don’t know what broke the cam, I was assuming the kdp fouled up somehow. I’m not sure though. I know the kdp is out & gone, also the camshaft retainer is broke. It’s a shame that a remanded engine that they don’t put the kdp retainer on it. Mike, that sounds a little better about pulling the lifters with a magnet.
What I've seen a time or two on short lived cams was the cam bearing lube holes weren't aligned with the holes in the block when installed. Plenty of splash makes them live for a bit and then they go dry and stop the cam from turning. I would recommend taking the engine out and doing a close inspection for a warranty claim.
So how do you change the lifters? It's easier to use dowels and rubber bands if your just pulling the cam, you don't have to remove the fuel injection pump . Bob
This motor only uses 1 cam bushing right behind the cam gear. Bob
Ok Bob, you’ve given some useful information. So this engine only has 1 cam bearing right behind the cam gear. I seen the dowel rod & rubber band trick on YouTube. Like I said earlier I’m not much of a diesel mechanic just learning as I go.
Pull the rocker covers , the rocker arms and pull the push rods to see what they look like. I meant did it quit running or did it just not start? Bob
It started & idled about 2 minutes & then died. I tried starting it back & would only crank never fired up. That’s how I’ve gotten to where im at with it .