LR4 5.0 Chain Guides actual problem?

[Pfunk951]

I imagine it's all about preserving the profit. Wikipedia counts 129,869 lr4s models 2010-2012.. Let's call it $1,000 at cost to replace them.. Just under $130m.. I imagine that McGovern needed that cash to buy ascots and destroy the visual heritage with the Disco5..

Mike

 

[Pfunk951]

Just got the truck back.. They left the chain in, said it was fine.. They installed the updated tensioners and guides, plus a slew of gaskets and seals.. New coolant and oil. They billed 19.25 hours..

Mike

 

[ktm525]

Thats not too bad . About a $3000 job in Canadian.

 

[Quijote]

I imagine it's all about preserving the profit. Wikipedia counts 129,869 lr4s models 2010-2012.. Let's call it $1,000 at cost to replace them.. Just under $130m.. I imagine that McGovern needed that cash to buy ascots and destroy the visual heritage with the Disco5..

Mike

That must be total Discovery 4 production. If so, as far as I know, only the 5.0L V8 is affected. I am pretty sure that is a small number of the total, as most LR4's (Disco 4's) sold worldwide are the diesel.

 

[ryanjl]

Just got the truck back.. They left the chain in, said it was fine.. They installed the updated tensioners and guides, plus a slew of gaskets and seals.. New coolant and oil. They billed 19.25 hours..

Mike

Wonder if they removed the heads?

What was the final bill?

 

[Pfunk951]

Quijote- Good call, I stand corrected.. I shot from the full production numbers, maybe the 5.0s were a 1/4 to 1/3 of that..?

All- I need a sanity check on something: RyanJL and I are digging into some of the details of the tear-down of this operation.. I checked the FSM and I'm thinking that pulling the heads is a layer deeper than this job goes.. I think the standard operation is that they pull the valve covers and replace the associated gaskets. Heads would surely require stud nuts and headgaskets..

Here's the damage:





Mike

 

[Ric in Richmond]

Just got the truck back.. They left the chain in, said it was fine.. They installed the updated tensioners and guides, plus a slew of gaskets and seals.. New coolant and oil. They billed 19.25 hours..

Mike

Did it sound better?

 

[ryanjl]

There have been a few more youtube videos concerning the timing chain issue that have popped online in the last 3 to 4 months.

There's a series here: https://www.youtube.com/channel/UCfdm97PbaUJAo8Q_Wd3ErcA

The uploader there (who may post on this forum?) did the job himself and just gives video updates along the way. It's interesting to note that, although he heard a knocking sound before the job, he didn't notice any discernible difference between his old chain and new chain, and it didn't seem like his old chain had worn or stretched at all. In the last post in his series, he opines that he only really needed to change the guides and the tensioners, but to do that you have to remove the front timing chain cover, and to remove the timing chain cover you have to remove the heads. Once you do that, the chain is right there and you might as well change it, too.

Removal of the heads appears to be the biggest PITA of the job, as it also requires removing the injectors, fuel rails, and a bunch of other stuff.

However, one commenter in the last video stated that it's possible to remove the timing chain cover by slightly flexing the valve covers (and not removing them). Which is something this RR owner did:

So, in light of all that, would it be possible to just replace the guides and tensioners as preventative maintenance, thus eliminating a bunch of painful steps? One key issue is to make sure the timing chain doesn't skip any teeth, but, so long as you can do that, the job looks a hell of a lot easier.

Yeah, looks like I misspoke in this post last week. You don't appear to need to remove the head to to the timing chain job; you need to remove the valve covers to do the whole thing. But it's removing the valve covers that requires removing fuel rails and injectors and thus becomes a major PITA.

Done by the book, the valve covers need to come off to remove the timing chain cover. But some have posted that you can just flex the valve covers without removing them to remove the timing chain cover. So long as you don't want to replace the chain, this is all you need to replace the guides and tensioners.

Looks like they removed PFunk's valve covers, though, going off of the parts used and the time it took.

 

[Pfunk951]

I didn't hear a lot of noise to begin with.. But now I hear -nothing- but injectors and fan. Everything up there sounds very smooth..

I think Ryan's headed on the right trajectory for this project, to get the valve cover just out of the way in order to get the chain cover off, and get at that top bolt on the chain rail. This should get it into a weekend job range..

This seems like an involved job, but by no means impossible. I did a clutch job on a 951 Turbo Cup that was 25 hours by the FSM- that Bi$#% took every minute of it. None of it was difficult, you just needed to have a plan, and organize. I see this as being no different, as if we are methodical and not throw all the bolts into a bucket on the tear-down, this can be more straightforward than it seems.

Mike

 

[cpatstone]

Has anyone here actually, personally done the tensioner/rail job, "zip tie" method, ie leaving the valve covers on?

I'm at the point where the rail is loose but I can't figure out how to actually wiggle it out. RR documentation for the procedure doesn't reference anything special. ???

BTW, mine would rattle/knock on warm start and other times just idling in traffic. The tensioner I removed clearly had a partially failed ratchet, and there was an adjacent pocket machined into the guide rail. and tiny non-magnetic sparkles in the oil on last change. '11 RR HSE 30k mi