Replacement for engine shock absorber

[sdoan]

A couple weeks ago the gear shifter in the bagel car was doing St. Vitus dance and determined to do something about it. The little engine shock absorber is shot so I figgured I could replace it with a spring under compression. I used a piece of 5/16" threaded rod and nuts and washers, and the original rubber bushings from the little shock. The brass tubing in the photo was used to make sleeves to protect the rubber bushings from the sharp threads on rod.



I found some rubber bushings that fit inside the spring to keep it centered on the threaded rod and kept them separated by a short section of heater hose. You can see rubber pieces inside the spring.


I installed it in the car with the spring toward the top and pushing up against the lower rubber bushing. Presumably the engine can push down against the spring or pull up against the rubber bumpers. In retrospect it probably would be good to have spring for both directions (i.e., both above and below the top mount) but this works for now, and the gear shifter doesn't hardly bounce at all.

[sdoan]

Here are some pics of the spring shock installed.





The clearance above the upper mount is very small, so if a spring were to be added to allow extension it would have to be below the lower mount.

[ARCHINSTL]

Bravo!
Great pix, too!
I moved this to the Repair Guides section.

What type of spring did you use? From a home improvement/hardware store? I have the little absorber still installed - and maybe shock absorber bushings could work on the lower. And I even have the rod from the bike shop!
When I replaced the engine and transmission mounts back in '06, most of this shake was eliminated - but some is still there. Gonna build this after I resolve the heater situation.
Thanks!
Tom M.

[sdoan]

The spring is from a very well stocked hardware store, but I'd bet you could find a similar thing at a Home Despot or Slowe's. The mountings are about 7.5" apart and the spring was a 5" length, and the wire diameter was 3.759 mm (if I remember correctly!). Basically I got the largest wire diameter I could find and a length that allowed me to compress it some.

I'm thinking of a revised design using the stock upper mount rubber bumpers and then pinching the lower mount between 2 shorter springs (one above and one below about the size of valve springs) so that the engine is freer to rock up and down. The preload on the spring can then determine how much rocking is allowed. I need to check to make sure there is enough clearance below the lower mount for that lower spring.

[bleakhorizon]

ok... so whats it like with a worn absorber....

[4wdchico]

ok... so whats it like with a worn absorber....

A whole lot like your car drives now, as the odds that your engine shock has next to no functional damping anymore are very, very high.

I did look thru an online listing of engine torque damper (the industry name for what we are talking about here) and did not come up with any suitable candidates that would not require new mounting brackets fabed.

I just went to ebay motors and found that there were 344 engine torque dampers for sale. The ones for the Mazda Miatas and the Nissan 240ZX's looked the most promising for our t4's

[ARCHINSTL]

This is a partial post from a thread I made in late '06 when I replaced the engine and trans mounts:

Incidentally, the "engine absorber" is not available anywhere *. Butler Toy in Indy (which is my favorite OE parts source) did an exhaustive search with other dealers nationwide, and came up with nada. The Mothership in CAL recently told me that I must use salvage parts. I asked if it is necessary, and could I make something out of a threaded rod and rubber bushings (I think takza had this as a suggestion a couple of years ago), and also if something similar would be available at an industrial shock absorber company.
It replied that "Yes, it is necessary, and Toyota does not recommend using anything else other than the original part, for fear of death, dismemberment, or destruction." OK, I added that last phrase. Anyway, it's a real Catch 22 situation for various models of Toyotas of the period. I wound up leaving mine mounted, although it is so "soft" that it seems irrelevant.
Tom M.
* Maybe Toy Canada has some?

Basically - Toy CAL was of no help. It would not give me ANY spec on the little absorber - even if other Toy models used it. It thought it was a pretty horsey response.
Tom M.

[sdoan]

Tom, I'm choosing to interpret their response this way:

Yes it is necessary or they wouldn't have put it in

It might be necessary only to sell the car because people don't like new cars that have a jumpy stick shift. By that standard it is just as necessary as optional air conditioning because some people won't buy the car if it does not have air conditioning.

My guess is that because the engine mounted above the transaxle and diff sits up so high there is more leverage on the rubber engine mounts so the engine jumps around more than an engine mounted lower. The additional movement might cause additional wear on the engine mounts and exhaust hangers, stress on the exhaust pipe and vibration of the shifter bearing pieces as well as scaring off the nervous buyer. So Toyota decided to damp out the movement.

Is it necessary to use their's? Of course! They don't make money otherwise.

Here's what I think. That any kind of damper that doesn't limit the movement so much that the mounts for it stress crack is probably OK. If the damper is too rigid the occupants can feel or hear the vibration and the mounts eventually stress crack. Too little restriction and it's like running without the damper. Really the thing I made is not a damper because it uses springs, but because the springs have a different rate than the existing mounts and because they work to limit the range of total movement they will tend to cut down the worst movement.

[ARCHINSTL]

I understand that it is necessary for ? reason, or the beancounters back in '82 (or before for Gen I) would not have permitted it.
What PO'd me was that Toy said it was necessary, but that none were available - anywhere, and "No-you can't substitute anything else." Its only answer to "Well, then, what do I do?" was that the part must be installed and to use a good salvage one - it had no answer when I asked for a source for "good salvage absorbers."
Seems like a Catch-22 to me.
You have the best idea so far, although the use of rubber bumpers is attractive - maybe with shock absorber stops?
Tom M.

[bleakhorizon]

whoa there, didnt mean to open a can of worms..... i know that Ford used them on the 60* V6's because of the imbalance of the engine and it helped to calm down the compression pulses at idle.... however being that it is an inline engine it shouldn't be as imbalanced...... i was considering rubber mounting a solid bar on mine as in my past experiences with autoX cars i have solid mounted engines to frames with turnbuckles and gained instantaneous throttle response (engine doesnt rotate on the mounts before transferring power out, and yes it is noticable) but suffered from hideous RPM induced vibration (In my 88 5.0 mustang i actually had it preloaded so much it tilted the engine to the drivers side about 15* if it wasnt like this i would rip the drivers motor mount apart after about 3 races)..... im not sure if mine is actually working, not sure if i care really with the little HP of this engine i doubt it even torque twists when throttled LOL...

[takza]

Strange thing is my shifter doesn't jump around at 250K miles...think I've seen this damper under there. I've seen hotrods with chains on the mounts to keep the engine in the bay.

Think the engine needs to move on the mounts to dampen vibration some...but not so much that it tears the mounts up. I think this spring and rod probably works OK...not much damping...but it limits movement.

[Petros]

Tom,
The answer is obvious, you can not drive your Tercel without the damper, so if you come down to the dealership they will be happy to sell you a new Toyota. You are just not understanding them.

[ARCHINSTL]

I know, I know - I just get so cantankerous in my dotage.
Sometimes I think Emily Litella is my sibling (but my kids think their Aunt is closer to Roseanne Roseannadanna).
Tom M.

[splatterdog]

Very few parts guys can think outside the box and even less care. The few times I've been to the dealer it's always a new guy that has never yet even heard about a T4. Even got a smartass reply once of "you must really like that car". I shot back "do you find that unusual with Toyota owners?" Man, parts guys sure can irritate me....

I wouldn't doubt there's still a few collecting dust on a shelf somewhere. But, would the time to find them be worth it?

I would agree with Tom on the necessity though. I know the car will get there without an engine shock. But no additional parts(mechanical) are added to any car without lots of consideration. I've seen simple things like drain plugs on automatics and rear axles that were eliminated in later production years. Some auto's don't even have dipsticks anymore either. Less cost,probably less maintenance now leading to a new car sooner. Brilliant! Until the gvmt owns you.....

Do the 2wd's have them?

[4wdchico]

Do the 2wd's have them?

Yes, the 2wd has the engine shock.