Big Bang At Reverse

[chrisis]

i have a 96 ford explorer xlt, 4.0 ohv with 4r55e tranny, 4wd with 136000 miles.

a few days ago i notice that if the car is in uphill position and try to put reverse, for 5-10 seconds the transmission is in newtral condition and then I HEAR A BIG BUNG when the reverse engage.

i also notice when the car is in cold condition a screeching sound is coming from transmission-transfer case area, but when the car gets warm the sound goes away.

i check the transmission fluid and it is in good level with a clean red color.

no leaks and no lights flushing in the dash.

any ideas???????????????????

 

[chrisis]

any suggestions?

 

[Creager]

Big bang in reverse!?! That would be a bad thing! We dont want the universe to go in... reverse!

ahah ok enough stupid jokes

I would suggest trying something a little different when you part on a hill. When you come to the stop, instead of putting the tranny in park, put it in neutral and stomp on the parking brake. Let the car sit and settle on the parking brake... then put the tranny in P. See if it still BANGS when you pull it out of park after using this sequential method?

Not sure about your sound man...

 

[chrisis]

i try and it went to Park without any noise.

is doing the noise only in reverse.

 

[chrisis]

any help would be very appreciated.

 

[wreckindave2024]

I'm having this same issue but I don't have to be on a hill. When I shift into reverse there's a big bang when it engages but no other gear does this. Does anyone have any idea what is going on here??

 

[C420sailor]

What trans?

Start with the simple things first. Check fluid, in park, on a level surface, engine running. Make sure you reference the appropriate dipstick ranges for hot/cold fluid.

Beyond that, it could be a few things:

Driveline slack. Worn u-joints, worn pinion bearings, etc.

Worn/damaged transfer case

Sticking reverse servo

Worn valve body and/or associated gaskets


I always recommend checking line pressures if you suspect the transmission. It’s good to be able to see what is happening inside the transmission when you select the gear and the bang happens. Weird pressure transients would be indicative of an internal trans problem

 

[Turdle]

It could be transfer case related. Try switching in and out of 4wd checking for a change of shift feel