subframe or motor mounts

[timbo]

I have a 1996 SHO and at low speeds and when the O/D is off, you get a thumping back and forth when going on and off the gas.

It appears to be a solid thunk and you feel it and can sense the rocking motion. Which should I look at Subframe mounts or motor?

Thanks in advance

PS, the subframe mounts (rear) were somewhat loose, I tighten, but did not seem to make a difference. I also did the "in gear test" and the engine seems to only move an inch or two.

But under load, it's a thunk!

 

[Ian Macoomb]

I just replaced my swaybar bushings last night and did the subframe bushings in September.

The subframe bushing clunk is a single clunk. I used to get it when I pulled away from a light or when braking. I also got a single clunk when turning the wheel. That's the subframe shifting.

The swaybar bushings gave multiple clunks most noticeable at low speeds. I even thought I might have a bad wheel bearing. I let it get really bad.

Anyway, I guarantee it's one of those or both. Might as well do them both because the other one will go shortly after the first one. That and it's just as easy to do both at the same time as doing the swaybar bushings by themselves.

 

[timbo]

Ian,

Thanks. I feel it when I get on or off the gas and/or when the drive-train is under load. (non 4th gear or low speeds when the car has no mommentum). You do feel it slightly in 4th, but it's much less.

I did the sway bar links last month.

How much are the bushings and was it easy (floor jack and stands enough)?

Tim

 

[f150fan]

The whole set (front and rears) from Ford parts network is like a hundred bucks US. FPS will hook you up.

 

[Ian Macoomb]

timbo:
Ian,

Thanks. I feel it when I get on or off the gas and/or when the drive-train is under load. (non 4th gear or low speeds when the car has no mommentum). You do feel it slightly in 4th, but it's much less.

I did the sway bar links last month.

How much are the bushings and was it easy (floor jack and stands enough)?

Tim

The bushings were about $50 Canadian ($30something US). The subframe bushings are about $100 but I'd suggest the solid aluminum ones. They're a bit more but they'll never wear out. You could do it with jacks and stands.

What you need to do is this:

1) Jack up the car and put a jack stand behind each front wheel.

2) Remove both front wheels

3) Remove the splash guard thingy under the nose of the car.

4) Loosen the 4 subframe bushings just a bit. This will require a breaker bar, some penetrating oil and maybe a cheater. Don't loosen them too much just get it started.

5) Then use the jack and a 2x4 to support the subframe near the rear. This is kinda important. Don't want the subframe dropping on you.

6) Slowly lower the Remove the two subframe bushings in the rear.

7) Now remove the two 13 mm bolts on the swaybar bushing U-brackets.

8) **** up new bushings with a silicone lubricant and install them on the bar.

9) Install the new subframe bushings in the rear and tighten up the bolts but not fully. New subframe bolts are recommended. Josh at SHOnut sells a recall kit that has the two bolts and a proper washer to go with the aluminum bushings.

10) Move the jack up to the front end and support the subframe near the front bushings.

11) Remove the front bushing bolts and lower the jack.

12) Remove the front bushings and install new ones.

13) Tighten all 4 subframe bolts and your about done.

 

[f150fan]

Is it a good idea to leave two of the bolts tight so we don't lose our alignment?

 

[SHODWN]

its more than likely motor mounts. the rear mount is a junk mount and rips eaisly. They when new can be reinforced to prevent this and they last twice as long. I complete urethane MM kit will be out before spring.

 

[Ian Macoomb]

f150fan:
Is it a good idea to leave two of the bolts tight so we don't lose our alignment?

Depends if you're replacing the SFB or not. It makes it easier to lower the rear subframe if you loosen the front a bit. Josh T also told me that you could cause damage to the subframe if you didn't loosen up the front ones with the solid aluminum bushings.

 

[timbo]

OK, I had time to look today and I had the wife gas it in gear (D & R) with the brake on. The subframe does not move one bit. The engine shifts a lot when looking from the bottom (you really notice and the exhaust connection).

It seems to pivit on the back mount, so my call is the front mount is wasted.

Anyone????????????????????????

 

[Ian Macoomb]

timbo:
OK, I had time to look today and I had the wife gas it in gear (D & R) with the brake on. The subframe does not move one bit. The engine shifts a lot when looking from the bottom (you really notice and the exhaust connection).

It seems to pivit on the back mount, so my call is the front mount is wasted.

Anyone????????????????????????

I think Kirk might be right. If it's only noticeable on acceleration or deceleration then it's not swaybar bushings. My SWBs made noise on every little bumb, being more noticeable at low speeds.

The SFBs made a single clunk when pulling away from a light or at the last second when coming to a stop and also a single clunk when turning the wheel in a tight parking space. Never any noise on a accel/decel from a roll.

 

[timbo]

OK, now with bloody knuckles, I have replaced the front mount and no change what so ever.

I looked at the rear mount and it appeared OK. Rubber appears to be in good condition.

I can grab the intake runners and shake the engine.

What am I missing. Could it still be the rear mount????

Signed, Bloody and ******!

 

[SHOZ123]

I have the front of my motor chained to the subframe with about a 1/4" slack in the chain. If both mounts on the passanger side are good then the only other one is the tranny mount. I had one of these go once.