4.0L SOHC 4.0 SOHC Manual/Mechanical Cam Chain Tensioners

[PetroleumJunkie412]

Interesting thread over in explorer world:

Manual Cam Chain Tensioner Install

I FINALLY got around to doing this job. I got my tensioners for $36 for the pair from eBay. Seller was hdesa.atelier. "Cam Timing Chain Tensioner Kit Manual Polaris RZR 1000 XP 900 570 Ranger 5813449". They came with crush washers and appeared to be very well made. This is on a '98 Explorer...

www.explorerforum.com

Apparently, Polaris used the same hydraulic cam chain tensioners Ford used with the SOHC. And Apparently the Polaris ones suck just as bad as the Ford ones. So the solution is to go to a manual set tensioner to avoid any further cam chain issues.

Elegant solution IMO.

Has anyone here done this one?

 

[85_Ranger4x4]

Generally if you replace them in time there is a fair chance the replacement hydraulic ones will outlive the truck.

I have never heard of them but I don't really follow much 4.0 stuff.

 

[Roert42]

Very interesting….

 

[Uncle Gump]

I never heard of it...

Does sound like an interesting option.

I still have a pair of Motorcraft tensioners NIB for my next maintenance change.

I might reconsider.

 

[PetroleumJunkie412]

I ordered a set of the standard length stainless ones. For $34, it's worth looking at them and giving them back to bezos if they suck.

At 195,000 mi, I'm on my second set, about to be on my 3rd. I definitely have chain rattle at startup if I don't prime the oil system first, but that's my fault since I used cloyes tensioners on the last change. Also running Valvoline restore and protect, which is doing some interesting things to the engine. More on that later with some Blackstone reports.

There is another Polaris option out there for a ratcheting tensioner that is hydraulically operated off the oiling system, but I haven't found anybody that's experimented with one of those yet. One of the things that they brought up that I believe is an issue with the stupid sohc is that when your oil system over pressures and high rpm, it will break the chains for guides due to excessive tension by the hydraulic tensioner. With my supercharger inbound from Magnum powers, this is something I'm trying to avoid. I wish I had a beater with an sohc in it to experiment with a little bit before I run it on my main engine, but sometimes the best science is done when you have everything to lose and have to get it right.

 

[lil_Blue_Ford]

I may have a spare SOHC sitting around, lol

 

[PetroleumJunkie412]

I may have a spare SOHC sitting around, lol

We should talk.

I have one, but it already jumped time.

What year block?

 

[lil_Blue_Ford]

We should talk.

I have one, but it already jumped time.

What year block?

No idea. Supposed to be a good running engine. It’s been sitting a few years though. The kid claimed it was a performance built engine but I saw nothing to support that claim. I was trying to figure out what to do with it when I ran into health problems. It’s also keeping what’s supposed to be a good 3.0 2wd automatic transmission company. Something else I need rid of.

Once I can get my shop done and my green Ranger I really want to sort through a bunch of this stuff and clean house. Only stockpile stuff I intend to use.

 

[PetroleumJunkie412]

Well. They're interesting little buggers. Machining is "China good," meaning some chips and residue on the slightly imperfect threads. Not aerospace quality, but will probably work for automotive application with some cleaning.

Quite heavy as I opted for the stainless ones. Not sure as to what the o ring is made of and if it will hold up to years of abuse in an engine.

Only complaint is the sloppy fit at the top bevel with regard to the copper gasket. Not great, as pictured. Still, probably usable.

Going to hang on to these ones with a printed copy of the install and adjustment procedure. They look like they would work, in theory. There is an extended version as well. May look at a set of those.

There is a lot of interesting info out there as to their application in Polaris. In theory, they prevent chain slap at startup, and prevent the Polaris issue of breaking cam chains due to sudden loss of RPMs. The other thing I saw tossed around on the Polaris and Explorer forums is they should prevent 4.0l cam chain issues due to oil overpressure; there is a theory with the explorer guys that the SOHC is incapable of high rpm running due to the hydraulic tensioners pushing too hard on the chain guides, leading to the chains breaking from over-tensioning. Interesting theory.

 

[Uncle Gump]

Air cooled VW oil pressure relief valves have an 18mm crushable sealing washer.

As said... my motorcraft tensioner came with no seals.

What size is that tensioner?

 

[PetroleumJunkie412]

As said... my motorcraft tensioner came with no seals.

I sprung for them when I did mine. I'll look at what the part number was when I get home. Bought four of them planning ahead for these.

What size is that tensioner?

Look like roughly the same size as stock ones. Some people on the explorer forum sprung for the extended ones since these are run almost entirely "in" when in the appropriate position. Only issue I saw was that the extended ones are aluminum. I'm not sure if that matters, though.

 

[Uncle Gump]

I sprung for them when I did mine. I'll look at what the part number was when I get home. Bought four of them planning ahead for these.



Look like roughly the same size as stock ones. Some people on the explorer forum sprung for the extended ones since these are run almost entirely "in" when in the appropriate position. Only issue I saw was that the extended ones are aluminum. I'm not sure if that matters, though.

Mine showed seals with the tensioners... Just didn't come with them.

My spare set is in a tote bucket... not sure which one. Thought maybe you could put a caliper on it and tell me if it is 18mm. VW pressure relief seals are $1.

 

[PetroleumJunkie412]

Mine showed seals with the tensioners... Just didn't come with them.

My spare set is in a tote bucket... not sure which one. Thought maybe you could put a caliper on it and tell me if it is 18mm. VW pressure relief seals are $1.

I'll toss one on it when I get home in a few days

 

[Uncle Gump]

Ahhh...

 

[PetroleumJunkie412]

Also, from the inventor of the manual tensioner mod: