Question about 1986 BMW 7 Series

1 Answer

Thump Thump Thump coming from rear when Hard Accelerating in 1st

When I hammer on the gas in first gear I hear and feel a thumping (thump thump thump) coming from the back of my car. It only happens if you accelerate fastand only in first gear. Could it be the rear diff? or u joint??

Its an Automatic 4 speed trans in an 1986 735i

Any help would be appreciated THANKS!!!

Posted by on

  • discofari Mar 05, 2009

    No its not the cv joint...

    I checked the driveaxle and it is loose and flopping around it is in need of a bearing i think


  • discofari Mar 08, 2009

    It was the driveshaft center bearing. the thumping was the driveshaft flopping around at low speed and banging on the bottom of the car because of the lack of a center support bearing. Once the vehicle is up pto speed the centrifical force stops it from flopping around

×

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that gotĀ 5 achievements.

    Governor:

    An expert whose answer gotĀ voted for 20 times.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Expert
  • 150 Answers

It does sound like one of the universal joints. If you can raise the back end off the ground engage gear and the faulty u/v joint will make the wheel jump. This will let you know which side it is

Posted on Mar 03, 2009

×

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

I hear and feel a thump when accelerating too fast from a stop. No thump if starting slowly. No problems accelerating once car is going. What could be causing this? Thump seems to be in the rear.


Transmission mounts are worn out and most likely your motor mounts too. Pretty straight forward job to replace but sometimes the bolts holding the motor mounts will be stuck requiring an impact wrench. Problem is that there is no room to get the impact near these bolts making a lift necessary.

Apr 14, 2015 | 2005 Cadillac SRX

1 Answer

97 ford ranger 4wd 4.0. Been to a trans man and 3 garages and no one can figure this out. When shifting park to reverse I have a big thump in te rear end and the body of my truck scrunches down. Won't...


Hi,
Does it do the same behavior when in 4WD LOW or 4WD High? If so, it's the transfer case or possible the front or rear differential.

GL,
Td

Oct 30, 2013 | Cars & Trucks

1 Answer

Thump and hesitation at takeoff not engine mounts


thump noise moving thru driveways is the lower control arm...

Feb 05, 2013 | 2005 Nissan Murano

1 Answer

I'm having a thump thump thump when excelerting and decelelrating. sounds and feels like it's coming from rearend


When was the last time you had your rear differential looked at or serviced? Basically when its happening something in your drive train is out of whack, so to fix it we need to look at the sequence of where the power goes, but if it sounds like its coming from the back,we'll start at the drive shaft itself, when it spins, it gives power to the rear differential, which is most likely where the noise is coming from. Driving should be limited while this problem is occurring because if any of the gears in the rear diff have become shaved or broken, the problem could get much worse while spinning with the pieces of gear are spinning around inside the still working gears. The first thing you should do is re-lubricate the gears in the rear, if this doesn't fix it, a trip to the shop is in order.

May 05, 2011 | Ford Ranger Cars & Trucks

1 Answer

I need to know how to get to the blend door in the heater area of my '92 chevy c1500. I was told that is what makes a thumping noise when the key is on or off.


this is some what normal, as long as it just once that you hear the noise (ie. you turn the truck on and thump, turn the truck of and thump) the doors operate off of vacuum lines in the engine. When you shut the engine off the vacuum goes away and *thump* the blend door snaps back to its normal resting position. then when you turn the truck on the vacuum then comes back and *thump* the door snaps back to its adjusted place.

If you feel that this is not what is going on, this diagnostic technique can help eliminate this condition
set the blend door to the hot side and start the truck and it should thump when the engine is on or off.
if you didn't get a thumping noise that is good it just means that the blend door is set to the hot side normally open.
.

Apr 18, 2011 | 1999 Chevrolet Silverado 1500

1 Answer

Check engine light came on today honda accord v6 2003 at 97k miles. car makes a thump sound when put into reverse hot or cold. sometimes when i turn and accelerate i can reproduce this feeling moving...


Take your car to a mechanic or your local auto parts superstore and have them read/scan the codes for the reason for the check engine light. A good place to start.

Apr 01, 2010 | 2003 Honda Accord

1 Answer

WHEN ACCELERATING IT GOES, THUMP THUMP THUMP, WHITCH GOES FASTER AS I ACCELERATE.


its a strut or shock please look into buying a strut for the side it sounds the worse hope this helps :)

Mar 24, 2010 | 1993 Toyota Corolla

1 Answer

I have a 2004 F150 with 103000 miles. Recently I have experienced a "clunk" or "thump" sound and sensation coming from the rear end when accelerating from a dead stop or from a slow coast...like in a...


if it is the pinion bearing located near the drive shaft it could cause slack and thump the drive shaft. with the truck jacked up the driveshaft would be sloppy near the rear up and down.

Feb 19, 2010 | 2004 Ford F150

1 Answer

Extreme thumping when accelerating through a turn


differential could be low on oil
wheel bearings could be going out
tires could be out of balance, likely

Sep 29, 2009 | 2002 Audi A4

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

516 people viewed this question

Ask a Question

Usually answered in minutes!

Top BMW Experts

Fred Sops

Level 2 Expert

271 Answers

Al Clark

Level 2 Expert

290 Answers

Doberman

Level 2 Expert

246 Answers

Are you a BMW Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...