My broncos driveline is making some sort of grinding noise upon acceleration in 1st and 2nd gear. Sometimes I can stop this noise from happening if I ease up on the clutch a little.

I still have the GKN style drive shaft and think this may be the culprit but it almost sounds as if it may be coming from the transmission/transfer case area.

I was just wondering if anyone else has experienced this noise, and what corrected it.....Makes my little Ron sound even rougher than it looks!

Also my valve train rattles badly after longer trips on the highway. After getting off the highway, if I shift long before you would normally shift throughout the drive range it clears up eventually, this one kinda leaving me stumped too....Heard something about cam bearing wear being a contributor to this, and that if you mount the thrust plate upside down it can remedy the problem. I would like to check the adjustment at my rockers and am unsure about how to check/adjust this on this particular engine. Ive really only ever rebuilt and worked on chevy small blocks and am now learning about the 2.9L.

Any helps greatly appreciated thank you.

 

The GKN style (aka: Tulip type) is basically about the same as a CV joint half-shaft. And when it's starting to fail? Gives about the same symptoms. Loud clicking/clunking sound, which can also sound like metal binding/crunching/grinding/etc...

I'm not going to bash the design, when it works? It's a decent design. However it's also extremely hard to service (lack of parts from local supply houses, and in general? It's not the easy one to pull apart, I've checked out a service manual--give me a set of U-Joints LOL!!)

Ours had a metal 'crunch' sound, kinda like binding metal--releasing...binding--releasing..etc.. And it did have a 'shimmy' as well at higher speed. (due to being worn, it couldn't maintain the rotational balance).

Just as with a half-shaft on a fwd car? It's lifespan can't really be told. Once it starts to wear and get noise? It can last days...months..years..or HOURS! All it needs to do? Is just bind up tight enough to snap the joint.

Most good parts houses will have replacement driveshafts (normally special ordered in from their warehouses) Ours ran about $210 plus core charge. And yes, the driveline 'shimmy' vanished, as well the metal crunch club. It's basically a short driveshaft, with normal U-Joints..and a neat slip joint built into the front section. You'll need to take some measurements of your current shaft, along with the date (month/year) of it's birthday (ford seems to have used a few different types for different option packages)

Now that the advertising is done LOL...

I'll let the engine experts get the valve train question answered. Mine does something along the same lines (the oil pressure when engine is at temp, sitting at a stop light does drop more then I'd normally expect)

S-

 

Noises - 1st and 2nd gear only or in all gears? If it's 1st and 2nd only, I would suspect it's more related to transmission internals. Have you checked the gear oil level? The clutch causing the noise to quiet also makes me wonder if your clutch disc or throwout bearing as well as the pressure plate might be contributing as well. I won't rule out the driveshaft, as I know those are known for going out - but I would suspect you'd have the noise througout the gears and at all speeds.

What grade oil are you using? I believe the quietest mine has run was when I've used 5W-30 (as the specs say for the engine) and a Purolator oil filter. It's always a good idea when changing the oil to do the engine flush on these - the oil pickup is known for clogging, and there are the usual issues with the oiling system in general. How many miles are on the engine? The only fail-safe cure I've heard of to get rid of the noise is to replace the oil pump, replace all the lifters, clean the oil pickup, replace all the bearings (rod, main, cam), and install the thrust plate for the cam upside down. These things are known to have some noise, but if you maintain your oil changes, they will still last until the engine requires a rebuild.

The only caveat on these engines is if they overheat - then you run the risk of cracked heads. Other than that, if they are well-maintained, they will run for many miles.

 

Well I just replaced the slave cyl. which has a new throw out on it, clutch disc. pressure plate master cyl. and the hyd. line between the two. The only thing I did not replace was the pilot bearing but it looked to be in a well lubricated state and I did not have the puller for it, I became frugal.

I believe I have read somewhere that it is not a good idea to just change the lifters and pushrods on these engines so that was not done when I rebuilt the heads and put them back on. I do believe that the oil pressure may be dropping in this thing every now and then especially after getting off the highway and coming up to a stop sign. Is it possible to pull the oil pan and do the pump without pulling the engine in these things? I have done this once in an older chevy pickup and never want to have it like that again.

Thanks for the input.

 

You can pull the oil pan and change the pump out. You'll have to pull off the distributor cap and unbolt the transmission / t-case mount so you can jack up the engine for clearance to remove the pan OR, take the motor mounts loose and jack the engine up that way as well. Not the easiest of tasks, but it is possible. Personally, if I were going to go that far, I'd just disconnect everything and pull the engine out so you can get to everything and go ahead and do all the bearings while at it - at the very least. The main part of the oiling problem deals with the bearings and bearing wear, if I am not mistaken.

Considering you have removed the heads, did you cold set your valvetrain when you reinstalled them? You have to do this in firing order, preferably, with both intake and exhaust valves closed. Run the adjuster down to zero lash, then 1 1/2 turns past that. If they are not set properly on reinstall, you end up with noise as well as other issues that can come up.

You're going to want to replace that pilot bearing / bushing... my '86 Ranger had a bad one for years and when the clutch finally went south, I ended up having to have the transmission overhauled because the input shaft got damaged. If I had been able to do the clutch myself, though, I would have probably figured out a workaround on that and saved the $$$ - clutch and transmission repair cost me $1200 total, not to mention the rental car I had to have while it was in the shop.