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Broken engine mounts, Again.

Posted: Sun Mar 30, 2008 12:33 am
by BEE-JAY
I have just torn my second set of new engine mounts. Just wondering if anyone else has had this trouble with aftermarket mounts. I might have to fork out for genuine and see if they are any better.

Re: Broken engine mounts, Again.

Posted: Sun Mar 30, 2008 8:55 am
by RUFF
BEE-JAY wrote:I have just torn my second set of new engine mounts. Just wondering if anyone else has had this trouble with aftermarket mounts. I might have to fork out for genuine and see if they are any better.
I have never had any luck with aftermarket mounts. The rubber allways seperates from the steel. I usually go to a wreckers and find a good set of second hand genuine mounts.

Posted: Sun Mar 30, 2008 2:37 pm
by Z()LTAN
u should put limiting chains on your mounts.. they disallow the rubber to stretch too far and thus breaking the mount.

Posted: Sun Mar 30, 2008 2:49 pm
by BEE-JAY
Limiting chains, you've obviously never seen a 3B at idle. After 5 minutes there wouldn't be a bolt left on the car or a tooth left in my head.

Posted: Sun Mar 30, 2008 3:03 pm
by revin
I remember years ago replacing the mounts in my old Lux.just doing them up by hand I managed to break the bolts inside the rubber on 2 sets of gearbox mounts and as you said.1st drive out I did rip the engine mounts.

I did what RUFF said get some from wreckers

Posted: Sun Mar 30, 2008 3:08 pm
by BEE-JAY
I don't mind paying for genuine ones (at cost price), But I don't want to fork out that much coin and find out that they are as useless as the cheap aftermarket ones.

Posted: Sun Mar 30, 2008 3:14 pm
by Z()LTAN
.....

you dont have the chains tight, u just make it so if the engine wants to move more than it should (like when the car is on the trail and hits a large bump) the chain will stop it moving too far and prematurely stressing the engine mounts.

Posted: Sun Mar 30, 2008 3:20 pm
by BEE-JAY
Again I will ask the question, Have you ever seen a 3B running at idle?

Posted: Sun Mar 30, 2008 3:36 pm
by locktup4x4
I have never had any luck with after market motor mounts. Unless they are the round bushing mounts like a leaf spring bushings. I have been run factory mounts for years. I take three links chain and weld one end to the chassis and weld the other end to the motor mount. I leave about a 1/2" gap in the center link. I also run a heavy duty transfer case mount that has the round bushings.

Jason

Posted: Sun Mar 30, 2008 5:42 pm
by dogbreath_48
I keep breaking the drivers side mount in my HJ75. Twice the stud has torn out of the cast wedge and once the rubber had torn - replaced with genuine. What am i doing wrong? Not like i'm running alot of horsepower :roll:

Posted: Sun Mar 30, 2008 8:03 pm
by BEE-JAY
I don't know what your doing wrong but I must be doing it twice as wrong because I'm breaking them with the power of a 3B with 310,000KM's on the clock. How are the genuine ones holding up?

Posted: Sun Mar 30, 2008 8:33 pm
by mud4b
power or kw does not come into it really, it is torque and traction and a single t-case bush that does this.although all the same strengthwise in a/f mounts, no one has asked what vehicle this is on and what mods to make them rip the rubber off the steal?


my info is almost the same a ruffs, although genuine (there is not really anyway to tell on wrecked vehicles) they are old and used, genuine is usually not that expensive ( when compared most of the time to used genuine or a/f mounts ) that is is not affordable to but new.

if you can weld and are not a complete dumbass/ not familiar with modding your own truck with you or your mates skills) then build some indestructible mounts.

these are made from the metal mounts on the block to a tube the right size (id) to house a rubber or nolathane bush with the mounts from there to the chassis. all in all separate it is only 7 pieces of metal for one mount, 6 flat and one bit of tube. it is very easy.

take the flat of the metal mount that bolts onto the engine block, trace it onto a flat plate (usually 6mm) then cut it out, clean the cut and drill the mounting bolt holes . work out motor height by supporting the engine on a jack/ engine hoist, then bolt the plate onto the engine(make sure engine and gearbox/ t-case is lined up the length of the overall unit, then work out length of supports to the tube that holds the bush, tack it all up once done. now trace the flat plate that mounts to the chassis (make it 6mm also) then cut it out and again drill the holes. now make the 2 flats that line up to the rubber/nolathane bush and tack those.

once the above is done you should go to the other side and repeat the process, once you have both mounts tack welded and sitting in there and bolted up then try weld some decent welds or tack in more positions for accuracy (welding 6mm plate to penetrate does move your angles due to heat) if tacking only remove mount then weld fully.

this might sound like a heap of work but it is only text here, when your doing it it is not hard at all for the novice or experienced welder/ fabricator
one more note of interest is the smaller the bush the more solid the mount is but you will get noticeable vibrations, the larger the bush ( 52mm) the better it will feel but you will still feel it compared to a std mount. the benefit of doing bushes this way is that even if the bush flog's out the engine will not move too far if at all.

cheers mark

Posted: Sun Mar 30, 2008 8:52 pm
by badger
the way mud4b has suggested is awesome, but on a diesel you are gunna get well shaken.

i use genuine nissan in my gq after having the same ussues with the cheapies
but i also loosly bind over my engine mounts with an old rachet strap just to limit them from streatching too far.
chain also works well but is slightly mor aggressive when it takes up and can tend to make the motor move sideways and tear the opposite mount instead

also try checking your box mounts and or making a torque arrestor on the transfer case similar to what mitsubishi runs on tritons etc

Posted: Sun Mar 30, 2008 9:30 pm
by Buggerific
Yeah I think I've read on here some guys who wrap old seatbelt around their bushes

Posted: Sun Mar 30, 2008 10:08 pm
by BEE-JAY
I can't believe you are telling people to solid mount their engines. Anybody who has done this should undo it ASAP. Your rubber engine mounts act as dampners for shock torque loads, without these the entire torsional shock load is being absorbed by your engine components( It would be a bit like going for a run on the road without shoes on).

Solid mounting engines is a common practice for earth moving machinery but these engines have massive rubber dampners on the outputs and then they run through a torque converter and still they suffer from shock loads.

Posted: Sun Mar 30, 2008 10:44 pm
by Z()LTAN
beejay are u thick? 3 times ive told you and 3 times you have thought i was talking about hard mounting the engine...

now you have done it again...

its not solid mounting its limiting, its still 100% held by the rubber untill it moves further than the mount should allow (this is when it stresses and breaks the mount)

doing this is common practice in all serious offroad vehicles and offroad racers.

Im sorry if i have come across hostile to you as its not my intention. Im just annoyed that you cant comprehend our advice.

Posted: Sun Mar 30, 2008 11:02 pm
by BEE-JAY
Prehaps if you bothered to read any of the other posts my last one might make a bit more sense to you. I don't need some amateur banging on at me about the half arsed job he has done. If you had read my original post you may have realised that I was asking if anyone else had had the same failure rate as me with aftermarket mounts, and if genuine ones fixed the problem. Be very careful about who you refer to as thick, I have read some rediculous statements made by yourself.

Posted: Sun Mar 30, 2008 11:17 pm
by BEE-JAY
I was going to leave it at that but since you've decided to be a childish little prick here goes.

While chaining an engine and solid mounting are not the same thing what do you think happens when the chain is pulled tight (I thought I should ask you since I'm so thick)? You lose all dampning effect of the rubber is what. Just when you engine is experiencing a massive torque load you remove the dampner. Now since I'm so thick I can't imagine what the result of this could be but I'm sure a smart lad like yourself could.

But then again I quite sure such a smart young mechanic such as yourself would realise all this and would not be dispensing potentially harmful information to novices who come on this forum seeking advice.

Posted: Sun Mar 30, 2008 11:45 pm
by mud4b
BEE-JAY wrote:I can't believe you are telling people to solid mount their engines. Anybody who has done this should undo it ASAP. Your rubber engine mounts act as dampners for shock torque loads, without these the entire torsional shock load is being absorbed by your engine components( It would be a bit like going for a run on the road without shoes on).

Solid mounting engines is a common practice for earth moving machinery but these engines have massive rubber dampners on the outputs and then they run through a torque converter and still they suffer from shock loads.


bee-jay. if your referring to me then get a grip bud, im not thick and my suggestion answered you question about standard gen mounts and a/f mounts. now if you think a round bush (rubber or nolathane) is any different to a point or as you explain it SOLID MOUNTING then think again...
really think what you have wrote, it does give flex or leeway ( although not as much as a standard type mount being it genuine or aftermarket but it is still the same compound to a point and will take the shock load) but it does not let go fully like a standard type mount, like i said the larger the bush the less the vibration. so use a largish bush it will be no different to your mount you have now but it will not snap or let go.

as said if this was directed at me, i am not thick in the slightest... im also not saying your thick, but it is not SOLID mounting like you suggest. if this was directed at me then cheers bud, have fun with your problem and in future like many on here don't bother asking questions if you don't want positive answers.

cheers mark

Posted: Mon Mar 31, 2008 9:05 am
by shorty_f0rty
bee-jay,

are these failures occuring due to wheeling or just normal daily driving?

I am pretty sure both my engine mounts have been replaced with aftermarket mounts and I haven't had ongoing issues with them since. I haven't been wheeling very much or too hard but have done a few trips and its been at over a year since i've replaced one.

So i can't say I have had the same problem as you in regards to going through engine mounts with a 3b.

hope this info helps.

Posted: Mon Mar 31, 2008 1:07 pm
by BEE-JAY
NO mud4b the thick comment was not directed at you. It was directed at
z()ltan in response to his comments. He seems to be having trouble accepting that he is posting a response to a question that was never asked, I wasn't asking for advice on reinforcing engine mounts. I understand that most people post on here in the interest of helping others but when you get a bug up your arse because people don't agree with your suggestion you need to have a good long hard look at yourself.

Here are some simple facts
1. If you use limiting chains or a bolt on your mounts when the chain or bolt is pulled tight you have lost all engine dampning.
2. Replacing rubber mounts with harder substances such as nolathane will increase the shock loading your engine components will have to absorb.
3. It may appear that your engine is delievering smooth rotary power but it is not, It is a cycle of power spikes and massive acceleration, it is just happening so fast you can't notice it. removing or limiting dampning effect will shorten engine life and could cause failure.

Please read the original posts carefully and try to respond with relevant information, accept that you could be criticised and have problems with your adive pointed out. And most importantly if you are offering advice that could cause damage to somebody elses vehicle make them aware of it, fixes that work for a unregisted weekend warrior could be very damage to a daily driver. And lastly if you don't know what you are talking about don't post, Don't repeat some load of crap you read off another forum that was posted by somebody else who also had no idea.

Now that that's over lets try again, I have a BJ42 with a 2" spring lift and 35's. After breaking the original engine mounts (which were nearly 25 years old so I forgive them) I replaced them with an aftermarket set, these lasted a few mounths and then the rubber and steel seperated, so I purchased a second set. I am in the process of fitting a supercharger and need to inspect of clearance between the engine and the chassis with the engine under full torque loading. So I placed the car in low, put it in first and with the hand throttle set at 1000 rpm held my foot on the brake and rode the clutch abit while my partner in crime inspected the clearance. As soon as I loaded the engine up it ripped the mount, the mount had only been in a few weeks and had done no time off road, this was the first time it had been put under load. Now my problem is this, If I am tearing mounts now I'm going to have no change once the blower is operating. I was just wondering if anybody else has had a large number of failures with aftermarket mounts and if anybody changed back to genuine mounts and fixed their problem. Please no advice on customising mounts to withstand the extra torque I am investigating the observed quality of aftermarket mounts. If I require advice on custom mounts I will post a topic as such. Sorry to be so longwinded but I tried to be informal and people took the topic and ran wild with it and then got offened when I pointing out the flaws in their unrequested advice.

Posted: Mon Mar 31, 2008 1:31 pm
by RUFF
So what are you wanting here that you have not allready received? Im confused :?

Your question has allready been answered twice regardless of what other answers/advice you have received.

How many people do you want to make the same replies?

Posted: Mon Mar 31, 2008 1:33 pm
by RUFF
As for your argument on the solid limiting set ups. Have a look around at some factory engine mounts on other vehicles before you try shooting others ideas down. Lots of factory mounts have a similar set up built into them. Gemini's and ford falcons are 2 just off the top of my head.

Posted: Mon Mar 31, 2008 1:44 pm
by BEE-JAY
To be perfectly honest the more answers I get that actually address the question I have asked the better, I wasn't aware that there was a limit on the number of relevant answers a post was allowed to recieve, because there certainly isn't a limit on unrelevant answers to questions never posed.

As for your point that OEM are using harder/limiting mounts, it doesn't change the fact that the less shock your mount absorbs the more your engine will have to absorb.SHOCKLOADS = BAD.

Posted: Mon Mar 31, 2008 1:47 pm
by RUFF
BEE-JAY wrote:As for your point that OEM are using harder/limiting mounts, it doesn't change the fact that the less shock your mount absorbs the more your engine will have to absorb.SHOCKLOADS = BAD.
Maybe to you but obviously auto manufacturers dont see a problem with it. But maybe they are just amatures?

Posted: Mon Mar 31, 2008 1:52 pm
by RUFF
BEE-JAY wrote:To be perfectly honest the more answers I get that actually address the question I have asked the better.
Ill be surprised if anyone bothers to answer your original question after your reaction to others trying to offer advice. It seams to me you allready have your own answers and are looking for people to assure you they are correct.


You only have 3 choices. Either continue replacing after market mounts that WILL fail, suck it up and buy some genuine mounts and see how you go or modify the way your engine is mounted.

Posted: Mon Mar 31, 2008 2:01 pm
by BEE-JAY
Or maybe these cars don't deal with the sorts of torques loads experienced by a diesel 4WD with a low range gear. Sorry I forgot that posting regularly on an internet forum makes you an expert on the distribution and dampening of engine loads.

Posted: Mon Mar 31, 2008 2:15 pm
by RUFF
BEE-JAY wrote: Sorry I forgot that posting regularly on an internet forum makes you an expert on the distribution and dampening of engine loads.
Sorry but your the one comming across like you think you are the expert here.

Good luck with your quest. Im all out of advice.

Posted: Mon Mar 31, 2008 2:25 pm
by RAY185
Just thought I'd post an answer to a question that was not asked.
BEE-JAY wrote:unrelevant
Irrelevant.

Carry on. :D

Posted: Mon Mar 31, 2008 2:52 pm
by BEE-JAY
It's probably a good thing that I'm a diesel fitter then and not an english teacher.