Big ol' Clunk in reverse
Laughing Gas
Joined: Feb 2016
Posts: 817
Likes: 27
My Bronco clunks pretty good going into reverse. You should have felt it when I went into 4 lo the other day.
I recall something with the trans (valve body, maybe?) that goes weird and doesn’t feather the engine and trans engagement. My vagueness is proportional to my knowledge in this subject. The Bronco shifts smoothly into drive, but reverse is another story.
You do have to suck out the fluid unless you want to pull the chunk. It’s a sucky job, zero pun intended.
I recall something with the trans (valve body, maybe?) that goes weird and doesn’t feather the engine and trans engagement. My vagueness is proportional to my knowledge in this subject. The Bronco shifts smoothly into drive, but reverse is another story.
You do have to suck out the fluid unless you want to pull the chunk. It’s a sucky job, zero pun intended.
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Cargo Master
Joined: Jan 2019
Posts: 3,369
Likes: 16
From: Caraway, AR
When the idle speed is high, the torque converter transfers more of the engine power through the transmission. So when you put it in gear, you have to hold the brake down harder. More torque is being transmitted through the transmission, so it will turn a reasonable clunk into a bang in the rearend.
This is the main reason why I do not run full manifold vacuum on these trucks with automatic transmissions. It makes the idle speed too high when it's not in gear, and too low when it is in gear with a automatic.
This is the main reason why I do not run full manifold vacuum on these trucks with automatic transmissions. It makes the idle speed too high when it's not in gear, and too low when it is in gear with a automatic.
No drain plug. Only a fill plug. The level of gear oil should be even with the fill plug.
To drain it you remove the cover. I have the 10.25, but yours is similar. Be sure to get a gasket before you change the gear oil. I used one of those permanent gaskets where you don't use sealer and it's reusable.
I'm in agreement with Franklin...adjust your idle as low as is practical. You don't want it stalling on you either.
To drain it you remove the cover. I have the 10.25, but yours is similar. Be sure to get a gasket before you change the gear oil. I used one of those permanent gaskets where you don't use sealer and it's reusable.
I'm in agreement with Franklin...adjust your idle as low as is practical. You don't want it stalling on you either.
No cover on the 9 inch. You more than likely have to suck it out. That is a lot of fun. That old gear oil is stinky stuff.
Once you get this thing going down the road, if the rearend is really noisy, I would plan on getting into it or swapping the whole thing out for a good one. If it's pretty quiet, I would live with a little play.
Once you get this thing going down the road, if the rearend is really noisy, I would plan on getting into it or swapping the whole thing out for a good one. If it's pretty quiet, I would live with a little play.
Thread Starter
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Cargo Master
Joined: Jan 2019
Posts: 3,369
Likes: 16
From: Caraway, AR
My Bronco clunks pretty good going into reverse. You should have felt it when I went into 4 lo the other day.
I recall something with the trans (valve body, maybe?) that goes weird and doesn’t feather the engine and trans engagement. My vagueness is proportional to my knowledge in this subject. The Bronco shifts smoothly into drive, but reverse is another story.
You do have to suck out the fluid unless you want to pull the chunk. It’s a sucky job, zero pun intended.
I recall something with the trans (valve body, maybe?) that goes weird and doesn’t feather the engine and trans engagement. My vagueness is proportional to my knowledge in this subject. The Bronco shifts smoothly into drive, but reverse is another story.
You do have to suck out the fluid unless you want to pull the chunk. It’s a sucky job, zero pun intended.
Lead Driver
Joined: Apr 2002
Posts: 5,318
Likes: 1,243
No cover on the 9 inch. You more than likely have to suck it out. That is a lot of fun. That old gear oil is stinky stuff.
Once you get this thing going down the road, if the rearend is really noisy, I would plan on getting into it or swapping the whole thing out for a good one. If it's pretty quiet, I would live with a little play.
Once you get this thing going down the road, if the rearend is really noisy, I would plan on getting into it or swapping the whole thing out for a good one. If it's pretty quiet, I would live with a little play.
I have to suck the gear oil out of my front Dana 50 diffy...there is a fill plug and you suck it out.
just seems there has to be a fill plug on the 9 inch...but can't verify that from here. Maybe you have to remove the carrier housing and bench fill it when servicing the diffy. Hopefully there is a filler plug. Otherwise I'm going to have to be permanently sorry for my pals that have the 9" rearend.
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Cargo Master
Joined: Jan 2019
Posts: 3,369
Likes: 16
From: Caraway, AR
Guess you could remove a bolt in about the middle and pump it in there, I assume they are through holes. Still haven't crawled under the truck. I plan to back it under the lean to. But weather is nasty and the windshield leaks, still(added caulk twice, may have to cave and cut the window out and reset it).
Lead Driver
Joined: Apr 2002
Posts: 5,318
Likes: 1,243
Guess you could remove a bolt in about the middle and pump it in there, I assume they are through holes. Still haven't crawled under the truck. I plan to back it under the lean to. But weather is nasty and the windshield leaks, still(added caulk twice, may have to cave and cut the window out and reset it).
Moderator
Joined: Jan 2001
Posts: 56,984
Likes: 2,738
From: Virginia
I believe the fill plug on the 9 inch is on the front casting of the housing, like the 10.25.
On the vacuum thing, yes I meant the distributor vacuum, sorry about that.
If you do have a rear cover on your diff, then you have a 8.8 rearend.
On the vacuum thing, yes I meant the distributor vacuum, sorry about that.
If you do have a rear cover on your diff, then you have a 8.8 rearend.
Lead Driver
Joined: Apr 2002
Posts: 5,318
Likes: 1,243
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Cargo Master
Joined: Oct 2016
Posts: 2,738
Likes: 217
From: Northern VA
I had this issue on my 86 300 c6. I just don't think you can replicate actual driving conditions by twisting the driveshaft with your hands. (no offense). Since I did this In no order I can't tell which was the acutal fix, but he clunk stopped after.
1. Replaced drive shaft u-joints with Moog.
2. Replace trans fluid/filter
3. Adjusted transmission reverse band
4. Tuned idle right in at 650 rpm----What does your hood label spec?
5. Replaced transmission vacuum modulator
6. Adjust throttle kickdown lever
-Emphasis on #1 and #4.
If that doesn't work..change your diff fluid and motor/trans mounts.
If that doesn't work learn to live with it?
Here's my thread from the recent past: https://www.ford-trucks.com/forums/1...violently.html
1. Replaced drive shaft u-joints with Moog.
2. Replace trans fluid/filter
3. Adjusted transmission reverse band
4. Tuned idle right in at 650 rpm----What does your hood label spec?
5. Replaced transmission vacuum modulator
6. Adjust throttle kickdown lever
-Emphasis on #1 and #4.
If that doesn't work..change your diff fluid and motor/trans mounts.
If that doesn't work learn to live with it?
Here's my thread from the recent past: https://www.ford-trucks.com/forums/1...violently.html
Thread Starter
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Cargo Master
Joined: Jan 2019
Posts: 3,369
Likes: 16
From: Caraway, AR
Finally scrapped all the dried mud from around the fill plug and cleaned it really good before removing it. She's full, got an amber color to it a little more tan than fresh motor oil and smells just like gear oil. No smell of burned oil. Maybe a touch on the thin side, but looks good to me.