Replacing engine lower mounting bush

rmattila · Post by **rmattila** » Sun Jan 23, 2011 11:07 am

Was pretty tight, but managed to do the job underneath the car, using the new bush as a driver, and the outer race of a scrapped front wheel bearing (with the inner diameter machined to 73 mm) as a pulling tool: http://www.rmattila.com/images/remontit ... vaihto.JPG . Luckily, the weather was nice: only -10 degrees C and quite dry. What a nice way to spend a Saturday afternoon engaged in healthy outdoor activities!

Heat was required quite a lot, and yet I managed to break one 10.9 M10 threaded bar by pulling too hard.

For making the work easier in the future, I made a driver tool from the old bush: http://www.rmattila.com/images/remontit ... painin.jpg. However, next time I change the engine, I will remember to check the condition of the bush before putting the engine in place.

MULLEY · Post by **MULLEY** » Sun Jan 23, 2011 6:14 pm

Love the piccies, but being a bit of a novice i'm a bit confused. I've got one of those engine bushes, but its a whole unit rather than just the rubber bush, why did you do what you did rather than replace the entire thing? Apologies for being a bit dim

rmattila · Post by **rmattila** » Sun Jan 23, 2011 6:22 pm

The rubber from the lower bush had broken, and the engine was able to move so much that the RHS inner driveshaft joint cup hit the surroundings when accelerating heavily. No need to change anything else besides the bush (# 1809 16 , cost 9,90 Euro), and besides, changing the entire mounting is quite a job: the driveshaft support bearing is in the same unit etc.

Should have checked the condition of the rubber last summer when I changed the engine, but somehow missed it at that time.

-Riku

MULLEY · Post by **MULLEY** » Sun Jan 23, 2011 6:27 pm

Aha, if the engine is supported from beneath, is there any reason why the whole bush can't be replaced easily? Or is it a case of having to take the driveshaft out justincase it gets damaged?

rmattila · Post by **rmattila** » Sun Jan 23, 2011 6:37 pm

There seems to be a confusion of terms: what I changed was the bush, including the metal parts (# 10 in the figure below), rather than the entire mounting unit (#3).

MULLEY · Post by **MULLEY** » Sun Jan 23, 2011 6:40 pm

Yeah, no 10 is what i'm on about, i thought that bush had an outer metal surround? This is what i presume you left in place & just replaced the rubber section inside it by making up the tool to push it out whilst popping new rubber straight in?

rmattila · Post by **rmattila** » Sun Jan 23, 2011 6:49 pm

No, I changed the entire bush, using the outer metal race of the new bush to push the old one out. In the picture below, from right to left:

aluminium bearing tool pulling the new bush inside the mounting unit
new bush, outer metal race visible
the engine mounting unit
scrapped front wheel bearing outer race, used as a pulling aid
the old bush (including the metal outer race) coming out from the mounting unit and inside the bearing race
bearing tool fork
spacers and a nut for providing the pulling force between the bearing tool fork and the aluminium bearing tool

Post by **Defender110** » Sun Jan 23, 2011 7:41 pm

IMHO it is much easier to take the old one out first before trying to put the new one in. A bit of heat will de-bond the old rubber if required and then take the blade out of a hacksaw frame and feed it through the bush ring before putting it back in the hacksaw frame, use this to cut through the old bush ring only and it will then all but fall out. Use emery tape to cleanthe housing face and coat with grease before easily using your puller to fit the new bush.

toddao · Post by **toddao** » Sun Jan 23, 2011 7:50 pm

Another job well done! But -10 degrees..? Positively tropical

Haven't you built yourself an inside working area yet Riku? (Or is that full?) Once you've built your own house that should be quite straightforward!

rmattila · Post by **rmattila** » Sun Jan 23, 2011 7:51 pm

Defender110 wrote:IMHO it is much easier to take the old one out first before trying to put the new one in.

I reached the same conclusion during yesterday's activities.

I took the ring of the old bush, machined 1 mm off the diameter, and welded a 15 mm plate with a 10 mm hole in the centre to the other end (figure). With this tool and sufficient input of heat, I hope the next change would be a bit less troublesome, as the old bush can be removed first before pushing the new one in. If not, then the hacksaw method will probably be the next approach..

-Riku

rmattila · Post by **rmattila** » Sun Jan 23, 2011 8:19 pm

toddao wrote:Haven't you built yourself an inside working area yet Riku?

You know, I actually thought about that for a while yesterday, when after lying a couple of hours underneath the BX doing this "quick job" I realized that I had managed to get my hair frozen to the ground: the heat flux from my strained brain had first caused the snow to melt, and when I subsequently took the head off the ground for the more accurate final phases of the job, the heat supply diminished causing the molten snow to freeze to ice. With my hair trapped inside.

But since that problem can be solved simply by getting a shorter haircut (or by learning to use a headpiece such as a tuque when lying in the snow), an indoor working area would probably be too high end a solution for my needs.

toddao · Post by **toddao** » Sun Jan 23, 2011 9:12 pm

/\

I find it bloody cold lying on the concrete floor of my garage at the moment with the minus sensation. You Vikings are well hard!

( how about a series of photos featuring some 'hair-engineering?'/short back'n'sides)

Gibbo2286 · Post by **Gibbo2286** » Sun Jan 23, 2011 9:39 pm

I'm with Defender on this, no need to go to all the trouble of making a special tool.

If the centre is already out use a small hacksaw with the blade inverted to cut a slot through the outer bush and you can push it out with your thumbs, clean and grease the casting and the new bush can be pressed in with a bolt and a couple of steel plates. Gibbo.

rmattila · Post by **rmattila** » Sun Jan 23, 2011 9:46 pm

The most embarrassing thing is that this was not even the first time.

My first frozen-hair occurrence was much more inconvenient: the house was even more under construction than now (i.e. not yet habitable even by our standards), so we lived in an apartment with a rented parking spot. On one cold Saturday afternoon, after changing the front suspension supply pipe I realized the said phenomenon having taken place, and the ice was so strong that I had only two options: to cut the hair using a knife (which I had not within reach, and was somewhat hesitant to ask passers-by if they would happen to carry one) or to use a hairdryer to melt the ice. The parking spot had a power socket for engine heater; however it was of the 1970's design, with the power supply switched on and off centrally at given times, and power was not due for another two hours. After considering my options for quite a while, I finally asked a passer-by to lend me her mobile phone, and called my Wife asking if she would mind coming to the parking lot after two hours and bring along a hairdryer..

rmattila · Post by **rmattila** » Sun Jan 23, 2011 9:54 pm

Gibbo2286 wrote:I'm with Defender on this, no need to go to all the trouble of making a special tool.

If the centre is already out use a small hacksaw with the blade inverted to cut a slot through the outer bush and you can push it out with your thumbs, clean and grease the casting and the new bush can be pressed in with a bolt and a couple of steel plates.

That's true; however, since the centre of the bush is somewhat wider (in the axial direction) than the outer ring, it is not quite as straightforward as with bearing races and such: you need to make some room for the centre, and I think therefore you need some kind of a "cup" instead of a straight plate on one side?

-Riku