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Discussion Starter #1
Hi All,

I have been sent a second hand flex plate to replace my suspected failed one. It looks like it has cracks across the three of the four inner set of holes. Never mind I wasn't charged for this one as I lost the first good one :crybaby2: .

I work at a sheet metal fabrication company with a laser and turrets etc. so I was thinking that it could be re-made with suitable material.

This brings to the question, what material could be suitable?
250grade mild steel or 350 grade or even 450?
spring steel?

Access to steel would not be the problem only knowing what one :think: .

Does anyone know what is going to be a suitable material, also would a thicker gauge help with longevity, or will this cause other issues with fitting and clearances.

Thanks,
Tyrone
 

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I"ve read about doubling up on flex-plates with uprated engines, don't recall where, but I think it just needed a bit of clearance work on the mounting surfaces to accommodate the extra thickness.

I imagine if you take the bad one to your metal supplier, they'll be able to match it.
 

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You'll want to use a plate that has good structural characteristics yet can flex. Most manufacturers use what was once termed as Type V, Grade 4, Class 70 or Class 60. The current ASTM classification is Grade H Class 70 or 60. Both are strong enough for the 4.6 by all means. If your steel supplier draws a blank, the details are in the ASTM specification A372.

Stress relieve the plate when you're done fabricating if the temps exceed 1200 F. If you're cutting with a plasma or laser you shouldn't have any problems.
 

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2010-2012 Range Rover MkIII / L322
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That could well be a Genuine Part one which RPI are selling.

How much is a Genuine plate in Australia?
 

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Discussion Starter #6
Hey thanks for your replies.

Will price a new one next week, not a popular mak here so probably needs to be through dealer.

I was advised to take the one i have to a heat treatment place and they can hardness test it, and or heat treat the one manufactured.

The one from RPi looks just like mine with the grinder marks around the bolts holes, what's that about? But by the time I convert to AUD's and shipping I cound have made ten of more for them! Thats the reason I though of going this route. I will probably bit the bullet and buy one anyway.

If it works out I'm happy to help others out if willing and make a few of them, shipping shouldn't be much.

The search will continue and will let you know.

Tyrone
 

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cyclone said:
Hey thanks for your replies.

Will price a new one next week, not a popular mak here so probably needs to be through dealer.

I was advised to take the one i have to a heat treatment place and they can hardness test it, and or heat treat the one manufactured.

The one from RPi looks just like mine with the grinder marks around the bolts holes, what's that about? But by the time I convert to AUD's and shipping I cound have made ten of more for them! Thats the reason I though of going this route. I will probably bit the bullet and buy one anyway.

If it works out I'm happy to help others out if willing and make a few of them, shipping shouldn't be much.

The search will continue and will let you know.

Tyrone
If it helps, I've just had a look at my old flex plate (now in 4 bits) and checked it against the new Genuine Part plate which has been bolted on this morning.

The new one looks about 50% thicker than the old one.
 

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Discussion Starter #8
Rich998a said:
The new one looks about 50% thicker than the old one.

That's interesting Rich998a, I was told that spacing would be an issue if it was thicker. Was anything else modified or changed.

Do you know the actual measurement of it?

The second hand one I have measures only 1.6mm.

Tyrone
 

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Looks can be deceiving. The old one ranges between 1.55 and 1.65 and the new one is 1.6.
 

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Does anyone know of a source in the states to buy a new oem flex plate?

My truck is in the shop in need of a flex plate, LR dealers wants $720 for a flywheel assembly, and i just want the flex plate! Atlantic british doesn't carry them either. There is roverland parts in florida but they only sell used stuff. My 96 4.6 is on it its 4th or 5th flex plate, odly they seem to go out every few years.

http://www.roverlandparts.com/range-rover-flex-plates.aspx
 

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pdxRR said:
My 96 4.6 is on it its 4th or 5th flex plate, odly they seem to go out every few years.

http://www.roverlandparts.com/range-rover-flex-plates.aspx
I'll second Dennis. The flex plate is meant to accommodate expansion of the torque convertor at higher engine revs. As I understand it, the convertor is basically a pressure vessel that, as pressure increases, it grows in length along the axis of the transmission shaft. If the convertor is weak or fatigued, or generating excess pressure, it may be able to expand beyond specifications. Note as well that the crankshaft position sensor is dependant upon a specific gap to operate correctly, so if you have any odd codes being generated at higher speeds it may mean something is moving too much. One remaining question is balance. It's my guess that the flex plate is balanced separately from the crankshaft and convertor, and that each is balanced within a certain limit. It could be possible that you have a perfect storm where the limits of balance for each work against each other to create a vibration.
 

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Sorry to hijack this tread. I thought I would ask since we are talking about flex plate. I am currently replacing my 2000 RR transmission. I am having a hard time to remove the 4 bolts between flax plate and torque converter. I have went up on my torque ranch to a 600 ft/lb, still won't loose. Any way around it?

Thanks in advance.
 

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Rich998a said:
If in doubt, burn it out. :twisted:

Maybe some heat but not too much. :naughty:
You are serious right? How much heat can I apply? A cigarette lighter is enough heat? On the bolt or around the flex plate?

Thanks again.
 

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Is that enough heat with hair dryer?

Is it possible to remove transmission without removing torque converter and/or flex plate??
 

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Aren't they the Torx type bolts or the standard bolt you are having problems with?



Mine were Loctited into place so needed a breaker bar to get them free. Probably better just heating the bolt heads with something. A gas lighter would be best perhaps?
 

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Thanks for the reply. It is standard Metric 13mm. There are 4 of them and they can be access through the inspection hole. Basically they are holding the flex plate and torque converter together. I managed to impact one of the four out and will try again this afternoon. So, a lighter is enough to heat the loctite? I am going to try that this afternoon.

Thanks again.
 

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Okay. Good news is I managed to remove 2 more bolts. So 3 removed and 1 more to go. Great!! Not to fast, I managed to strip the last bolt. So, now I have to figure a way to get that stripped bolt out. Man, I was so exciting I got the bolts out and BAM!! Thanks for the heat solutions, it does help to loosen the bolt make it easier to retrieve.

If you have any idea to remove stripped bolt, please do give me some suggestions. I am going to try those tool to retrieve stripped bolt from Sears to see if that works.

Thanks again.
 
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