Replace Screw/Bolts for Reinforment Plate?

bosstones · 04-08-2019, 08:56 AM

Was going to get under the coupe to do some work (motor mounts, trans mounts, and starter). Looking at New TIS, it says to replace the screws/bolts when reinstalling the plate. For those that wrench their cars more, do you really use fresh HW whenever you have to take off the plate?

Efthreeoh · 04-08-2019, 11:13 AM

I've been wrenching on BMWs for 30 years. IMO, BMW calls for replacing hardware unnecessarily. I only replace hardware that is true stretch-to-yield, such as aluminum hardware for the N52, and critical fasteners that have high torque values (i.e. 120 lb-ft) and if fail can cause loss of vehicle control. I'd not replace the hardware for the reinforcement plate.

An example, the 14MM steel bolts used for mounting the E90 subframe. When you replace the pan gasket on the N52 in the E90 3-series, the front sub frame must be detached and dropped from the chassis. BMW calls for replacing the 4 mounting bolts. I didn't replace the ones on my car. They were not corroded and in fine shape. They are very large steel bolts that can take easily 3-times the torque spec BMW requires. They are still in place 3 years and almost 100,000 miles later.

bosstones · 04-11-2019, 10:31 AM

I'll play it safe and pick up new bolts. Looking thru past threads where the plate had to come off....the bolts are stretch to yield.

chickdr · 04-11-2019, 09:17 PM

I had mine off years ago to do the UUC transmission mount replacement. Reused the bolts and have had no issues.

StickMon · 04-13-2019, 01:04 PM

If you torque them per spec you stretch them.
How many time do you recon you can stretch them?
I keep a sack of them and just replenish when I have less than 8 left.

On the other hand if you under torque them and don't stretch them, you may be fine.

bosstones · 04-14-2019, 07:59 AM

I torqued mine. Gotta get that that satisfying 'click'.

StickMon · 04-14-2019, 10:42 PM

If you click them to 43 ft*lbs (58 Nm) and leave it at that, you can probably reuse them.
The kicker is you're then supposed to turn them another 90°, rear first, then front.
That's when they supposedly stretch.

David70 · 04-15-2019, 08:18 AM

I do question how many of the bolts that are supposed to be replaced really need to be, especially when steel to steel and pretty low torque. Most of the time I replace them because it is a small part of the job and cost.

Why is it my wheel bolts/nuts (depending on car) are torqued at I think 90-100 ft. lbs. but seem to good for infinite uses? They must not be stretch bolts but if they don't need to be why are so many other bolts required to be?

elerner61 · 04-15-2019, 09:14 AM

Quote:

Originally Posted by StickMon

If you click them to 43 ft*lbs (58 Nm) and leave it at that, you can probably reuse them.
The kicker is you're then supposed to turn them another 90°, rear first, then front.
That's when they supposedly stretch.

I'm not a burly guy (skinny ass Mountain Biker). Getting that 90° on the last two bolts even with a breaker bar is always "fun".

StickMon · 04-15-2019, 12:23 PM

Yep. I weigh about a buck-30 so I have way too little gravitational attraction.
I just shoot out from underneath the car, and I don't want to brace against the jack stands.
I think I read somewhere that you're not supposed to use an impact wrench, but no other choice.

bosstones · 08-04-2020, 09:52 PM

Does anyone have the correct P/N for the bolts? I need to get under the engine again but it looks like I wasn't charged for the bolts when I got the at the stealership last time. I guess the employee forgot he tossed them in the box of oil I bought at the same time.

RealOEM shows 2 different P/N's but neither seem to match the correct quantity needed:

07119905655 - M10X40-10.9ZNS3, qty 2
31106772199 - M10X35-10.9ZNS3, qty 14 (although it looks like 2 are for each pull rod)

zed_fan · 08-04-2020, 10:09 PM

It's the M10x35 bolts https://www.realoem.com/bmw/enUS/sho...diagId=31_0779

I was just under there a couple weeks ago. They are nearly $4 a bolt and you need 8. I just ended up reusing my bolts...

bosstones · 08-04-2020, 10:30 PM

Quote:

Originally Posted by zed_fan

It's the M10x35 bolts https://www.realoem.com/bmw/enUS/sho...diagId=31_0779

I was just under there a couple weeks ago. They are nearly $4 a bolt and you need 8. I just ended up reusing my bolts...

Ah...wrong plate altogether.

Thanks!

04-08-2019, 08:56 AM	#1
bosstones Lieutenant Colonel 1154 Rep 1,543 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	Replace Screw/Bolts for Reinforment Plate? Was going to get under the coupe to do some work (motor mounts, trans mounts, and starter). Looking at New TIS, it says to replace the screws/bolts when reinstalling the plate. For those that wrench their cars more, do you really use fresh HW whenever you have to take off the plate? __________________ - Jeff bosstones' flickr
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04-08-2019, 11:13 AM	#2
Efthreeoh General 17267 Rep 18,716 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I've been wrenching on BMWs for 30 years. IMO, BMW calls for replacing hardware unnecessarily. I only replace hardware that is true stretch-to-yield, such as aluminum hardware for the N52, and critical fasteners that have high torque values (i.e. 120 lb-ft) and if fail can cause loss of vehicle control. I'd not replace the hardware for the reinforcement plate. An example, the 14MM steel bolts used for mounting the E90 subframe. When you replace the pan gasket on the N52 in the E90 3-series, the front sub frame must be detached and dropped from the chassis. BMW calls for replacing the 4 mounting bolts. I didn't replace the ones on my car. They were not corroded and in fine shape. They are very large steel bolts that can take easily 3-times the torque spec BMW requires. They are still in place 3 years and almost 100,000 miles later.
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04-11-2019, 10:31 AM	#3
bosstones Lieutenant Colonel 1154 Rep 1,543 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	I'll play it safe and pick up new bolts. Looking thru past threads where the plate had to come off....the bolts are stretch to yield. __________________ - Jeff bosstones' flickr
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04-11-2019, 09:17 PM	#4
chickdr Lieutenant Colonel 140 Rep 1,990 Posts Drives: 2006 M Roadster Join Date: May 2009 Location: Buford, GA iTrader: (0)	I had mine off years ago to do the UUC transmission mount replacement. Reused the bolts and have had no issues.
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04-13-2019, 01:04 PM	#5
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	If you torque them per spec you stretch them. How many time do you recon you can stretch them? I keep a sack of them and just replenish when I have less than 8 left. On the other hand if you under torque them and don't stretch them, you may be fine. __________________ Warning: May contain traces of nuts.
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04-14-2019, 07:59 AM	#6
bosstones Lieutenant Colonel 1154 Rep 1,543 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	I torqued mine. Gotta get that that satisfying 'click'. __________________ - Jeff bosstones' flickr
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04-14-2019, 10:42 PM	#7
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	If you click them to 43 ftlbs (58 Nm) and leave it at that, you can probably reuse them. The kicker is you're then supposed to turn them another 90°, rear first, then front. That's when they supposedly stretch. __________________ Warning: May contain traces of nuts.*
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04-15-2019, 08:18 AM	#8
David70 Colonel 1567 Rep 2,665 Posts Drives: 06 Z4M Coupe - 13 Cadillac ATS Join Date: Apr 2012 Location: Cincinnati, OH iTrader: (1)	I do question how many of the bolts that are supposed to be replaced really need to be, especially when steel to steel and pretty low torque. Most of the time I replace them because it is a small part of the job and cost. Why is it my wheel bolts/nuts (depending on car) are torqued at I think 90-100 ft. lbs. but seem to good for infinite uses? They must not be stretch bolts but if they don't need to be why are so many other bolts required to be? __________________ 2006 Z4M Coupe - Stromung exhaust, ZHP knob, stubby antenna, clutch delay delete
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04-15-2019, 12:23 PM	#10
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	Yep. I weigh about a buck-30 so I have way too little gravitational attraction. I just shoot out from underneath the car, and I don't want to brace against the jack stands. I think I read somewhere that you're not supposed to use an impact wrench, but no other choice. __________________ Warning: May contain traces of nuts.
	Appreciate 0 Quote

08-04-2020, 09:52 PM	#11
bosstones Lieutenant Colonel 1154 Rep 1,543 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	Does anyone have the correct P/N for the bolts? I need to get under the engine again but it looks like I wasn't charged for the bolts when I got the at the stealership last time. I guess the employee forgot he tossed them in the box of oil I bought at the same time. RealOEM shows 2 different P/N's but neither seem to match the correct quantity needed: 07119905655 - M10X40-10.9ZNS3, qty 2 31106772199 - M10X35-10.9ZNS3, qty 14 (although it looks like 2 are for each pull rod) Attached Images __________________ - Jeff bosstones' flickr
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08-04-2020, 10:09 PM	#12
zed_fan Private 21 Rep 70 Posts Drives: 2006 Z4MR, E60 M5 6MT Join Date: Jul 2020 Location: AZ iTrader: (0)	It's the M10x35 bolts https://www.realoem.com/bmw/enUS/sho...diagId=31_0779 I was just under there a couple weeks ago. They are nearly $4 a bolt and you need 8. I just ended up reusing my bolts...
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