I think I need motor mounts

[modelageek]

I have a slight bang when giving the truck gas at low rpms.......I just replaced the clutch and PP not much of a change........ I got under and looked at the MM but cant see anything obvious. I think they are the rubber ones......when revving the engine the engine does jump up on one side.......I read a few posts one person said an 18mm rathecting wrench works good.........it is a little tight.I cant even figure it out because the MM on rock auto look a different..........any feedback on diagnosing and or installing them would be appreciated....

 

[scotts90ranger]

sounds more like a U joint, but on the motor mount they are usually fairly obvious

is it a manual transmission? if so, when you start from a stop how far does the shifter tilt? around an inch is normal, 5-6 and the mount is shot if it tilts bad going forward, drivers side mount, tilts bad in reverse passenger side mount.

 

[modelageek]

Scottsranger. The shifter does not move. I suspected ujoints also but they seem fine. Maybe it is the rearend or tranny

 

[dbest1a]

Would it be the same sound in an automatic as a 5 speed?

 

[steve63]

possibly a transmission mount?

 

[modelageek]

possibly a transmission mount?

sorry forgot to mention i replaced the tranny mount................the "sound" I think would be the same as an Auto because it happens when the truck is in gear and the rpms are low and I am coasting...when I give it gas there is a bang..........like the ujoint has slack in it...........

 

[Tedybear]

Back in the day we used to check motor mounts by putting the car/truck into either reverse or drive. Foot on the brake and give it a little pulse of gas while watching the engine. If you do it and the motor "lifts" more then it should? Mount is shot.

Now 'n days if you did that? Fair chance the cooling fan would smack into the shroud. Now that will make a noise you won't soon forget.

S-

 

[Bryan22]

definitely doesn't sound like a motor mount. It's super obvious in a manual gear box equip ranger, the shifter goes to about 5th gear when accelerating in 1st.

Does it only do it when you're moving or also in neutral?

 

[4b316]

Jack up one tire in the back and check and see how far the tire rotates til it hits,maybe a spider gear?

 

[Bryan22]

was kinda thinking that too when he said clunk... but if it was a bad gear it'd make it at all rpms when moving, not just low rpms.

 

[steve63]

sounds to me like it could be somewhere in the rear of the truck,when u take off theres a lot of twisting force that has to be curtailed by the suspension back there,so possibly could be maybe something loose in the rear end,rear springs,carrier bearing (if you have one),or even a loose exaust mount.

 

[modelageek]

sounds to me like it could be somewhere in the rear of the truck,when u take off theres a lot of twisting force that has to be curtailed by the suspension back there,so possibly could be maybe something loose in the rear end,rear springs,carrier bearing (if you have one),or even a loose exaust mount.

thanks for all the feedback......there is no grinding at all. it feels like the driveshaft/engine/tranny,rearend has slack in it. if the engine rpm are up and i let off the gas and then give it gas I do not feel the clunk..............if I let off the gas and I am gliding with the rpm down.......and I give it gas that is when I get the bang/clunk...........like something is catching up........

 

[scotts90ranger]

parking brake on, tranny in neutral get underneath and twist the driveshaft, how much does it turn? and does it move up and down or just turn? if it just has rotational slop in the rear diff I say loose spiders, especially if it's just a few degrees.

 

[modelageek]

parking brake on, tranny in neutral get underneath and twist the driveshaft, how much does it turn? and does it move up and down or just turn? if it just has rotational slop in the rear diff I say loose spiders, especially if it's just a few degrees.

it does not seem to have much play in it. if i put a mark on the diff housing and turn the DS it will move about 1/4 inch.

if I am on the higway in 5 gear and coasting at 50 if I let off the gas and then give it gas I hear/feel the bang. almost like the drivetrain has slack in it and then catches up

I f I am in another gear, say 3rd gear and i have the engine rpm's high and it is at the point where I really should be in a higher gear. if i let off the gas and then give it gas I do not feel/hear the bang.........it is like there is no slack in the drivetrain



I am thinking of pulling the diff cover to change the fluid anyways. I dont know much about the diff

 

[modelageek]

I am going to change the fluid in my diff......this is what I was going to do. please give me ffedback if you dont agree

-remove cover
-scrap clean cover and housing
-clean with brakecleaner
- apply RTV Blue to housing and immediatly install cover and finger tight
- wait one hour then tighten securely.........does anyone now the torques spec for the bolts?
- wait 24 hours and then fill with gear oil. I have a 7.5 with an open diff. I was going to use 80w90 or 75w90 gear oil should I bother with synthetic or just use the dino stuff........TIA