Friday 16 June 2017

Chrysler Grand Voyager flexplate replacement

Here is the long write-up of the saga of my Chrysler Grand Voyager 2.8CRD automatic. It's a 2004/2005 model (sometimes called the facelift edition) and I love it. It's the second of the Grand Voyagers I've owned as I think they're great bits of kit, comfortable, big (7 seats, and they are BIG comfy armchair type seats) and lots of gadgets.

A quick summary of jobs/checks covered here:

  • Balance Shaft Assembly on base of engine
  • Accessory belt removal/replacement
  • Oil Sump removed
  • Balance Shaft Assembly removed
  • Injector return leak test
  • Flexplate removal (Separation of the gearbox and the engine)

However, as it turns out some of their parts, mechanically aren't so great. My first Grand Voyager unfortunately died with a cracked block. Yes that's right, the actual block had a crack it it (I suspect this damage was from when I suddenly lost all oil one day travelling for work, limped it to the office, filled back with oil and hoped for the best. Replacement oil cooler and other parts didn't help).

So onto my current GV and this one suddenly developed a really bad rattle noise at idle. The noise got worse over a very short period, perhaps 4-5 days and the noise only happened when at idle. Increasing the engine revs either in idle or drive would lose the noise.

Here is the video of the noise I was experiencing:

So I went about diagnosing this noise, as it was unusual. One automatic gearbox specialist and two general garages listened to the noise and came up with conflicting and bad news.
One said it didn't sound like the automatic box itself but it was related.
One said it was the balance shaft assembly and was difficult to replace.
One didn't know but wouldn't go near it as it was a VM engine (VM Motori which is an Italian engine manufacturer known for their diesel and agricultural engines). Apparently VM engines in consumer vehicles don't have a very good track record.

So after that I decided to go do my own testing. First option was to remove the accessory belt, this would discount:

  • air conditioning clutch and pump
  • power steering pump
  • alternator
  • idlers and pulleys
To remove the belt was relatively straight forward, you can slacken it using the tensioner, just get a relatively large ring spanner over it and twist it towards the rear of the car. This removes the tension. I found I had to attach it to a screwdriver to get a little more length/movement on it to make it easier. Once you have the tension off slip the belt off.
You may need to also remove the steering pump belt. On mine this is on the outer of the main drive shaft pulley and is a short separate belt to the power steering pump. To slacken this you need to undo the bolts around the power steering pump and turn the pump so it slackens the belt. This is quite a tricky job as it is very tight when held in place and took many attempts to get this right.

No change after removing the belt, so it wasn't that. Next was to drop the oil sump and take a look inside, firstly at what is in the bottom of the sump and secondly what I could see into the bowels of the engine. Dropping the sump came up with a few little items in there, nothing big or significant:

PS: Nobody could explain what these were or how they got there, best guess is some previous work left them lying around. But nothing there that would explain it fully.

Peering up at the underneath of the engine not much could be seen, this is due to the balance shaft assembly covering the entire base of the engine.
this photo is looking up at the driver side (right hand drive car) so you can see the main big end bearing (top middle).
Top left and the oily pipe is the suction intake for the oil pump.
Middle to bottom (with the two central rings) is the balance shaft assembly covering the rest of the engine big end bearings.

As this was suggested as another possible issue, I then removed the balance shaft assembly.

NOTE1: DO NOT do this unless you have to! This proved a dead end and was very problematic re-attaching at the correct timing sequence point (You have to use the timing kit an 'set' the flexplate to the correct point in the cycle, then use the timing pin in the balance shaft assembly to set those).

That is the balance shaft assembly when removed. The two cogs on the right connect to the base of the engine crank to spin the balance shafts. The two shafts have counterweights on them and simply spin in a counter-rotating manner. They are supposed to remove knock and judder from the older diesel engines and make them smoother. There are records of these being removed without any harm to the vehicle (A lot of Sebring owners remove them for the 1-2bhp performance increase they give). BUT when removed the oil distribution system is altered, there is a hole that feeds the balance shaft with pressurised oil for lubrication so removing it you have to tap off these feeds, etc. It's OK for a test but not long term.
Again, I started the engine with the balance shaft removed (sump refitted and oil back in) but the noise was still there.

Next was the injectors, to see if they could somehow be causing the noise. So I did the leak test on them initially. This is done by removing the diesel return pipe off the injectors and see how much is being returned. A very large amount indicates an injector problem.
The injectors are at the top of the engine. Remove the plastic cover, and the rubber cover (If you have them) and you'll see the four injectors. On the picture below the injector is in the middle of the photo with the return pipe on the top with the clip (braided hose). The high pressure inlet is the metal pipe off an angle to it and it's power is the plastic clip going off the middle bottom of the photo.

To test for return leak you remove the clip and hose from the top and place a pipe to a jug or bottle to collect the liquid. You do this on each injector. Because the middle injectors have an in and out 'join' pipe you need to feed two pipes to your collecting jug or bottle.
Each injector has a small metal clip on the top as you can see in the photo above, use a screwdriver or pliers to remove the metal clip, once removed the plastic fitting will lift up and out of the injector. You then have to prise the pipe off it so you can attach a temporary pipe going to your collection jug/jar/bottle.

Here is a quick video showing the diesel being collected (See how I've used multiple pipes or blocked pipes so I can collect from each injector):

Then the output after a few minutes of engine running:

Not much at all which is good, shows the injectors are working relatively efficiently. So again, this wasn't the source of problems.

Now this limited what I could do. It was either major engine failure or it was to do with the automatic transmission.

At this point, comparing to others on the internet it suggested the flexplate. The flexplate is used on automatic gearboxes and on a manual would be called the flywheel. It bolts to the main engine crank, has the toothed gear for the starter motor to engage with and then bolts to the torque converter.
(a bit of background info on flexplate is here: though it is a promotional/marketing video!)
So this looks like the source of my trouble. The problem? To get to the flexplate you separate the auto gearbox from the engine, i.e. the bell housing bolts come out and you split the two.

So, to do this you need to get the car up on jack stands securely, take both wheels off and then remove the hubs to allow movement along the drive shaft. We didn't remove the drive shaft as we had enough movement from removing the hubs:

Above you can see the hub removed (and supported with straps). We did the same for the brake caliper too.

With those removed, you need to get to the automatic gearbox top mounts, brackets and cables. Remove the battery, it's plastic base and the bits around it (Remove the wiper assembly top too as that gives you access).

Here you can see looking down towards the automatic gearbox (battery and base removed). You can also see the bolts that hold the gearbox in (two bolts towards middle right of photo, there are another two hidden above those). Also to the left middle you can see the shift lever which we detached (simple clip removal).
The starter motor needs removed (More awkward as you get at it through the gaps you can see here, the main obstacle being the water cooling pipe in the left middle of picture.

You need to loosen all the bolts attaching the gearbox to the block and mounts, as you will be fully detaching the gearbox (torque converter and housing) from the engine enough to remove the flexplate.
In the above photo you can see the flexplate teeth and mount where the starter motor fits (Starter motor was just moved and jammed up out of the way, see it middle right on the photo here with the black ring round it)

 Identifying where all the bolts that need to be removed was one of the hardest parts. There were 3 towards the rear of the automatic gearbox, one of which we had to remove using a long socket extension bar fed from the driver side wheel arch right under the body to the middle. Once the breaker bar did it's job they were all loosened.

Remember not to remove them! That's what holds in the automatic gearbox. Towards the front of the automatic gearbox are the automatic fluid pipes. These had enough flex in them so were not removed.
Also remove the electrical connections to the automatic gearbox (These power the solenoids for the automatic shift. As a note we forgot to reconnect these and caused the gearbox to run in limp mode).

Finally to separate we unbolted the flexplate bolts that were holding the flexplate to the torque converter. These were difficult to get at from the bottom (the supposed flexplate access hatch).

However, once logic was engaged, you can see these bolts clearly through the hole where the starter motor sits, so that's where you bolt/unbolt. DO NOT try through the flexplate access hatch at the bottom which seems how some may have done this, it chews the bolts up! When we removed the bolts they were VERY chewed up and not in good condition at all. (So we sourced replacements. Not OEM from Chrysler but high tensile similar replacements)

Once we were happy with this, we used two hydraulic jacks, one to support the right (when looking towards back of vehicle from engine bay) of the engine (engine mount loose) and one to support the entire gearbox. Once supported slowly removing the bolts (The last three holding it on were accessed through the passenger (left) side wheel arch, as we removed these we made sure the jack was holding the weight (i.e. no pressure on the bolts when removing). Once loose we had to 'wobble' the gearbox along moving the jack on it's wheels slightly to separate the gearbox from the engine.

We separated it enough so that we could reach into the bell housing and undo the central bolts holding the flexplate onto the main driveshaft. Once removed we could bring the flexplate out and inspect it.
Here is the removed flexplate. The central bolt holes are the ones that connected it to the driveshaft and the outer ones to the torque converter.

As you can see there are some serious cracks and damage around the central ring, and it was only just holding itself together!

You can see from this photo how much light is coming through the cracks/damage to the centre of the flexplate. This is typical flexplate damage and causes the noises heard at idle (i.e. mainly when the flexplate isn't under a large amount of strain/pressure)

So now to do the reverse, to install the new flexplate, line it up similar to the one we just removed.
We used threadlock when bolting it back into place to ensure they wouldn't come loose and also ended up replacing the bolts that connect the flexplate to the torque converter as these were badly chewed up. We're unsure how they were in such a bad way, other than potentially somebody doing similar work on the flexplate in the past and not tightening securely (i.e. spanner slipping on the nut, etc).

Once the flexplate was re-attached to the driveshaft we needed to bring the two halves back together, again using the jacks we slid them back together and aligned them using a couple of the fixing bolts to ensure it was lined up correctly.
Re-attaching the bolts around the bell housing and the rest of the gearbox to hold it in place. We didn't tighten to full torque yet as wanted to get them all bolted and lined up first before tightening up fully.

Once it was joined up, starting to tighten each bolt back up and reconnecting everything we disconnected (Remember any connectors you disconnected to reconnect!) and re-assemble which was relatively straight forward.
Back together and starting the engine all sounded good, no rattles or noises and everything was working great.

One other point to note, if you find that your gearbox won't shift out of the lower gears (So sticks in 1 or 2 gear) then this points to the solenoid or 'electronic' shift. In our case it was because we'd left the connector off on the gearbox ECU and so it wasn't communicating with the main ECU correctly. An easy fix luckily!

I hope this helps anyone else with a similar problem, or for a few tips on getting it apart and back together. I welcome comments and info on this one from anyone in a similar position or had similar problems.

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