"Slapping" transmission

Let me see if I can describe this...
Put in 4.10 gears and a LockRite locker at the same time (which replaced
stock 3.54's and open spider gears) in a AMC 20 differential with 33" tires.
Ever since, the manual transmission gears go "SLAP, Slap, slap slap" when
you are decelerating, in-gear, with the clutch pushed in. It feels like the
spinning driveshaft's "slapping" the gears to keep up. It's really
noticeable when moving slowly in 1st or 2nd.
Don't think it's got anything to do with the locker other than possibly a
little more slop in the diff. Is it because I installed such low gears?
Combination?
P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
really sounds like a miniature jack hammer over 35 in neutral but that's a
different post.
Regards,
Drink
76 CJ7, GM 350, TPI, NV4500, DANA300
Dana30/AMC20 w1-pc axles, LockRite, 4.10s

I recently heard that kind of noise when decelerating in gear...

I pulled over and disconnected my front hubs before my now dead
driveshaft u-joint could take out the yoke too.

I would sure be checking those u-joints out really carefully. The
vehicle needs to have the wheels blocked and in neutral when you crawl
under to see if there is any play or rust stains around the U-joint
caps.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

Drink wrote:
>
> Let me see if I can describe this...
> Put in 4.10 gears and a LockRite locker at the same time (which replaced
> stock 3.54's and open spider gears) in a AMC 20 differential with 33" tires.
> Ever since, the manual transmission gears go "SLAP, Slap, slap slap" when
> you are decelerating, in-gear, with the clutch pushed in. It feels like the
> spinning driveshaft's "slapping" the gears to keep up. It's really
> noticeable when moving slowly in 1st or 2nd.
> Don't think it's got anything to do with the locker other than possibly a
> little more slop in the diff. Is it because I installed such low gears?
> Combination?
> P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
> really sounds like a miniature jack hammer over 35 in neutral but that's a
> different post.
> Regards,
> Drink
> 76 CJ7, GM 350, TPI, NV4500, DANA300
> Dana30/AMC20 w1-pc axles, LockRite, 4.10s

No, Mike. That's not it. The U-joints are fresh and in great shape. It
did it before. As a matter of fact, it started after changing to 4.10 gears
and the LockRite. Since then, absolutely everything's been upgraded and
swapped out except the Dana300. I don't wanna lure anyone into a diagnosis
of the transfer case, though, because it really sounds like the tranny.

Here's the timeline recap: Swapped gears&locker myself; slapping has been
there ever since.
Then dropped in a 350 V-8, NV4500 with all new clutch and components,
reinstalled the orig. Dana300, shortened/balanced driveshaft w/new U-joints,
had a pro RE-setup the AMC20 just to be sure.
Jim

"Mike Romain" > wrote in message
...
>I recently heard that kind of noise when decelerating in gear...
>
> I pulled over and disconnected my front hubs before my now dead
> driveshaft u-joint could take out the yoke too.
>
> I would sure be checking those u-joints out really carefully. The
> vehicle needs to have the wheels blocked and in neutral when you crawl
> under to see if there is any play or rust stains around the U-joint
> caps.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> (More Off Road album links at bottom of the view page)
>
> Drink wrote:
>>
>> Let me see if I can describe this...
>> Put in 4.10 gears and a LockRite locker at the same time (which replaced
>> stock 3.54's and open spider gears) in a AMC 20 differential with 33"
>> tires.
>> Ever since, the manual transmission gears go "SLAP, Slap, slap slap"
>> when
>> you are decelerating, in-gear, with the clutch pushed in. It feels like
>> the
>> spinning driveshaft's "slapping" the gears to keep up. It's really
>> noticeable when moving slowly in 1st or 2nd.
>> Don't think it's got anything to do with the locker other than possibly
>> a
>> little more slop in the diff. Is it because I installed such low gears?
>> Combination?
>> P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
>> really sounds like a miniature jack hammer over 35 in neutral but that's
>> a
>> different post.
>> Regards,
>> Drink
>> 76 CJ7, GM 350, TPI, NV4500, DANA300
>> Dana30/AMC20 w1-pc axles, LockRite, 4.10s

Strange...

It was my 'front' driveshaft that went out by the by and my u-joint is
less than a year old.....

I cooked it by being in 4x4 on dry paved roads for too long.

Could it be because the lockRite is being pushed with wheel load instead
of drive load? Is there an adjustment in there?

Mike

Drink wrote:
>
> No, Mike. That's not it. The U-joints are fresh and in great shape. It
> did it before. As a matter of fact, it started after changing to 4.10 gears
> and the LockRite. Since then, absolutely everything's been upgraded and
> swapped out except the Dana300. I don't wanna lure anyone into a diagnosis
> of the transfer case, though, because it really sounds like the tranny.
>
> Here's the timeline recap: Swapped gears&locker myself; slapping has been
> there ever since.
> Then dropped in a 350 V-8, NV4500 with all new clutch and components,
> reinstalled the orig. Dana300, shortened/balanced driveshaft w/new U-joints,
> had a pro RE-setup the AMC20 just to be sure.
> Jim
>
> "Mike Romain" > wrote in message
> ...
> >I recently heard that kind of noise when decelerating in gear...
> >
> > I pulled over and disconnected my front hubs before my now dead
> > driveshaft u-joint could take out the yoke too.
> >
> > I would sure be checking those u-joints out really carefully. The
> > vehicle needs to have the wheels blocked and in neutral when you crawl
> > under to see if there is any play or rust stains around the U-joint
> > caps.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> > Canadian Off Road Trips Photos: Non members can still view!
> > Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> > (More Off Road album links at bottom of the view page)
> >
> > Drink wrote:
> >>
> >> Let me see if I can describe this...
> >> Put in 4.10 gears and a LockRite locker at the same time (which replaced
> >> stock 3.54's and open spider gears) in a AMC 20 differential with 33"
> >> tires.
> >> Ever since, the manual transmission gears go "SLAP, Slap, slap slap"
> >> when
> >> you are decelerating, in-gear, with the clutch pushed in. It feels like
> >> the
> >> spinning driveshaft's "slapping" the gears to keep up. It's really
> >> noticeable when moving slowly in 1st or 2nd.
> >> Don't think it's got anything to do with the locker other than possibly
> >> a
> >> little more slop in the diff. Is it because I installed such low gears?
> >> Combination?
> >> P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
> >> really sounds like a miniature jack hammer over 35 in neutral but that's
> >> a
> >> different post.
> >> Regards,
> >> Drink
> >> 76 CJ7, GM 350, TPI, NV4500, DANA300
> >> Dana30/AMC20 w1-pc axles, LockRite, 4.10s

I have 4.10 gears and the full Detroit in my AMC20, and there is no noise.

You said, " Swapped gears&locker myself; slapping has been there ever
since." Then you said that you replaced the trans and motor. If the noise
was there BEFORE you swapped the trans, what makes youthink the noise is
coming from the trans?

I don't recall if you have a CJ5 or CJ7, but if you have a double-cardan
joint in the driveshaft, perhaps the center joint is toast. Mine recently
took a bye and made a clunking noise, but it was mostly on acceleration and
your noise is on decelleration.

You also said that "absolutely everything has been swapped out, except the
D300." Why does the D300 escape scrutiny? Also, the gear set (R&P) has to be
set up properly, did you do that? It can create noises that can travel up
the driveshaft and sound like the transmission.

Knowing from personal experience how much torque steer there can be in a CJ,
have you removed the rear drive shaft and drive on the front one to see if
the noise remains? If the noise goes away, you'll have a pretty good chance
that the trans isn't the object of your obsession, if the noise remains,
then you still have the tcase in the picture, but you'll know the rear gear
set is okay.





"Drink" > wrote in message
...
> No, Mike. That's not it. The U-joints are fresh and in great shape. It
> did it before. As a matter of fact, it started after changing to 4.10
> gears and the LockRite. Since then, absolutely everything's been upgraded
> and swapped out except the Dana300. I don't wanna lure anyone into a
> diagnosis of the transfer case, though, because it really sounds like the
> tranny.
>
> Here's the timeline recap: Swapped gears&locker myself; slapping has
> been there ever since.
> Then dropped in a 350 V-8, NV4500 with all new clutch and components,
> reinstalled the orig. Dana300, shortened/balanced driveshaft w/new
> U-joints, had a pro RE-setup the AMC20 just to be sure.
> Jim
>
> "Mike Romain" > wrote in message
> ...
>>I recently heard that kind of noise when decelerating in gear...
>>
>> I pulled over and disconnected my front hubs before my now dead
>> driveshaft u-joint could take out the yoke too.
>>
>> I would sure be checking those u-joints out really carefully. The
>> vehicle needs to have the wheels blocked and in neutral when you crawl
>> under to see if there is any play or rust stains around the U-joint
>> caps.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's
>> Canadian Off Road Trips Photos: Non members can still view!
>> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
>> (More Off Road album links at bottom of the view page)
>>
>> Drink wrote:
>>>
>>> Let me see if I can describe this...
>>> Put in 4.10 gears and a LockRite locker at the same time (which replaced
>>> stock 3.54's and open spider gears) in a AMC 20 differential with 33"
>>> tires.
>>> Ever since, the manual transmission gears go "SLAP, Slap, slap slap"
>>> when
>>> you are decelerating, in-gear, with the clutch pushed in. It feels like
>>> the
>>> spinning driveshaft's "slapping" the gears to keep up. It's really
>>> noticeable when moving slowly in 1st or 2nd.
>>> Don't think it's got anything to do with the locker other than
>>> possibly a
>>> little more slop in the diff. Is it because I installed such low gears?
>>> Combination?
>>> P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
>>> really sounds like a miniature jack hammer over 35 in neutral but that's
>>> a
>>> different post.
>>> Regards,
>>> Drink
>>> 76 CJ7, GM 350, TPI, NV4500, DANA300
>>> Dana30/AMC20 w1-pc axles, LockRite, 4.10s
>
>

Sure isn't any adjustment for the locker. It simply replaces the spider
gears and, instead of distributing torque to the fast wheel, it locks the
slow wheel. The only thing that strikes me is that it amounts for a little
more play than the spider.
In straight movement, the locker should be out of the picture since both
wheels are turning at the same rate just like the spider.
So, could it be that a) the very low gear is doing it, b) the added
backlash of the locker allows enough play to "slap" the tranny gears, or c)
both?
Thanks for the advice, Mike (and anyone else who has any ideas).
Best Regards,
Jim

"Mike Romain" > wrote in message
...
> Strange...
>
> It was my 'front' driveshaft that went out by the by and my u-joint is
> less than a year old.....
>
> I cooked it by being in 4x4 on dry paved roads for too long.
>
> Could it be because the lockRite is being pushed with wheel load instead
> of drive load? Is there an adjustment in there?
>
> Mike
>
> Drink wrote:
>>
>> No, Mike. That's not it. The U-joints are fresh and in great shape.
>> It
>> did it before. As a matter of fact, it started after changing to 4.10
>> gears
>> and the LockRite. Since then, absolutely everything's been upgraded and
>> swapped out except the Dana300. I don't wanna lure anyone into a
>> diagnosis
>> of the transfer case, though, because it really sounds like the tranny.
>>
>> Here's the timeline recap: Swapped gears&locker myself; slapping has
>> been
>> there ever since.
>> Then dropped in a 350 V-8, NV4500 with all new clutch and components,
>> reinstalled the orig. Dana300, shortened/balanced driveshaft w/new
>> U-joints,
>> had a pro RE-setup the AMC20 just to be sure.
>> Jim
>>
>> "Mike Romain" > wrote in message
>> ...
>> >I recently heard that kind of noise when decelerating in gear...
>> >
>> > I pulled over and disconnected my front hubs before my now dead
>> > driveshaft u-joint could take out the yoke too.
>> >
>> > I would sure be checking those u-joints out really carefully. The
>> > vehicle needs to have the wheels blocked and in neutral when you crawl
>> > under to see if there is any play or rust stains around the U-joint
>> > caps.
>> >
>> > Mike
>> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> > 88 Cherokee 235 BFG AT's
>> > Canadian Off Road Trips Photos: Non members can still view!
>> > Aug./05 http://www.imagestation.com/album/in...?id=2120343242
>> > (More Off Road album links at bottom of the view page)
>> >
>> > Drink wrote:
>> >>
>> >> Let me see if I can describe this...
>> >> Put in 4.10 gears and a LockRite locker at the same time (which
>> >> replaced
>> >> stock 3.54's and open spider gears) in a AMC 20 differential with 33"
>> >> tires.
>> >> Ever since, the manual transmission gears go "SLAP, Slap, slap slap"
>> >> when
>> >> you are decelerating, in-gear, with the clutch pushed in. It feels
>> >> like
>> >> the
>> >> spinning driveshaft's "slapping" the gears to keep up. It's really
>> >> noticeable when moving slowly in 1st or 2nd.
>> >> Don't think it's got anything to do with the locker other than
>> >> possibly
>> >> a
>> >> little more slop in the diff. Is it because I installed such low
>> >> gears?
>> >> Combination?
>> >> P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
>> >> really sounds like a miniature jack hammer over 35 in neutral but
>> >> that's
>> >> a
>> >> different post.
>> >> Regards,
>> >> Drink
>> >> 76 CJ7, GM 350, TPI, NV4500, DANA300
>> >> Dana30/AMC20 w1-pc axles, LockRite, 4.10s

"Drink" > wrote in message
...
> Sure isn't any adjustment for the locker. It simply replaces the spider
> gears and, instead of distributing torque to the fast wheel, it locks the
> slow wheel. The only thing that strikes me is that it amounts for a
> little more play than the spider.
> In straight movement, the locker should be out of the picture since both
> wheels are turning at the same rate just like the spider.
> So, could it be that a) the very low gear is doing it, b) the added
> backlash of the locker allows enough play to "slap" the tranny gears, or
> c) both?
> Thanks for the advice, Mike (and anyone else who has any ideas).
> Best Regards,
> Jim
>

4.10 is not very low ratio. There is 4.56, 4.88, and 5.<something> that are
lower. The R&P have an adjustment for mesh that is critical, and you could
be feeling/hearing the affects of having any one of several adjustments not
set right. The pinion gear has to be spaced properly with washers, and if
there is slop, the pinion can slide in and out of the pumpkin. The ring gear
has to be mounted well to the carrier, and if the bolts are not tightened
well, the ring gear will give you troubles. The ring and pinion have to be
adjusted properly to each other, and there will be noises if this adjustment
is not correct.

Thanks Jeff.
I haven't really ruled out the T-case. But, this became an issue
immediately upon R&P swap/Locker install. I'd try some of the other advice
but I'm in the middle of the project (for the past many years I hit a
deal on the engine and haven't swapped the front gears yet. Gotta get the
front shaft cut to fit as well. I had a professional transmission shop set
up the rear end Again to rule out my own incompetence. Haha! And, if you
can believe it, I'm considering swapping to Dana44's or GM 10/12 bolt axles
after everything I've invested.
You make a good point about it not being the trans. Although the slapping
sounds like its in the gearbox, I know it's differential-related and that's
what I don't get yet.
I'll have to see if I can ssttrrreeeeetch the front shaft just enough to
give it a walk around the block. Pretty sure it's not long enough, though.
P.S. How difficult would it be to just say, "to heck with it" and put in
Dana44's from a 79 Cherokee (front discs, six-lug wheels)? Or, would a
10/12 bolt from a suburban or blazer be better?
Jim
'76 CJ-7: Dana30 / Chevy 350 TPI / NV4500 / Dana300 / AMC20

"Jeff Strickland" > wrote in message
...
>I have 4.10 gears and the full Detroit in my AMC20, and there is no noise.
>
> You said, " Swapped gears&locker myself; slapping has been there ever
> since." Then you said that you replaced the trans and motor. If the noise
> was there BEFORE you swapped the trans, what makes youthink the noise is
> coming from the trans?
>
> I don't recall if you have a CJ5 or CJ7, but if you have a double-cardan
> joint in the driveshaft, perhaps the center joint is toast. Mine recently
> took a bye and made a clunking noise, but it was mostly on acceleration
> and your noise is on decelleration.
>
> You also said that "absolutely everything has been swapped out, except the
> D300." Why does the D300 escape scrutiny? Also, the gear set (R&P) has to
> be set up properly, did you do that? It can create noises that can travel
> up the driveshaft and sound like the transmission.
>
> Knowing from personal experience how much torque steer there can be in a
> CJ, have you removed the rear drive shaft and drive on the front one to
> see if the noise remains? If the noise goes away, you'll have a pretty
> good chance that the trans isn't the object of your obsession, if the
> noise remains, then you still have the tcase in the picture, but you'll
> know the rear gear set is okay.

Just to add my two cents in, I also have an AMC 20 with full detroit, 4.10
gears, D 300, but AX15 tranny with adapter, no tranny noise or problems, I'd
be checking the D300 too, and as I just helped my daughter replace her u
joint in her double cardon drive shaft at only one year old, ( driveshaft,
not daughter ), we couldn't get any movement out of it in nuetral with no
load on it, but as soon as we dissconnected it the cap that had no bearings
left in it fell off, so like Mike said check those again too.

"Jeff Strickland" > wrote in message
...
>I have 4.10 gears and the full Detroit in my AMC20, and there is no noise.
>
> You said, " Swapped gears&locker myself; slapping has been there ever
> since." Then you said that you replaced the trans and motor. If the noise
> was there BEFORE you swapped the trans, what makes youthink the noise is
> coming from the trans?
>
> I don't recall if you have a CJ5 or CJ7, but if you have a double-cardan
> joint in the driveshaft, perhaps the center joint is toast. Mine recently
> took a bye and made a clunking noise, but it was mostly on acceleration
> and your noise is on decelleration.
>
> You also said that "absolutely everything has been swapped out, except the
> D300." Why does the D300 escape scrutiny? Also, the gear set (R&P) has to
> be set up properly, did you do that? It can create noises that can travel
> up the driveshaft and sound like the transmission.
>
> Knowing from personal experience how much torque steer there can be in a
> CJ, have you removed the rear drive shaft and drive on the front one to
> see if the noise remains? If the noise goes away, you'll have a pretty
> good chance that the trans isn't the object of your obsession, if the
> noise remains, then you still have the tcase in the picture, but you'll
> know the rear gear set is okay.
>
>
>
>
>
> "Drink" > wrote in message
> ...
>> No, Mike. That's not it. The U-joints are fresh and in great shape.
>> It did it before. As a matter of fact, it started after changing to 4.10
>> gears and the LockRite. Since then, absolutely everything's been
>> upgraded and swapped out except the Dana300. I don't wanna lure anyone
>> into a diagnosis of the transfer case, though, because it really sounds
>> like the tranny.
>>
>> Here's the timeline recap: Swapped gears&locker myself; slapping has
>> been there ever since.
>> Then dropped in a 350 V-8, NV4500 with all new clutch and components,
>> reinstalled the orig. Dana300, shortened/balanced driveshaft w/new
>> U-joints, had a pro RE-setup the AMC20 just to be sure.
>> Jim
>>
>> "Mike Romain" > wrote in message
>> ...
>>>I recently heard that kind of noise when decelerating in gear...
>>>
>>> I pulled over and disconnected my front hubs before my now dead
>>> driveshaft u-joint could take out the yoke too.
>>>
>>> I would sure be checking those u-joints out really carefully. The
>>> vehicle needs to have the wheels blocked and in neutral when you crawl
>>> under to see if there is any play or rust stains around the U-joint
>>> caps.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Drink wrote:
>>>>
>>>> Let me see if I can describe this...
>>>> Put in 4.10 gears and a LockRite locker at the same time (which
>>>> replaced
>>>> stock 3.54's and open spider gears) in a AMC 20 differential with 33"
>>>> tires.
>>>> Ever since, the manual transmission gears go "SLAP, Slap, slap slap"
>>>> when
>>>> you are decelerating, in-gear, with the clutch pushed in. It feels
>>>> like the
>>>> spinning driveshaft's "slapping" the gears to keep up. It's really
>>>> noticeable when moving slowly in 1st or 2nd.
>>>> Don't think it's got anything to do with the locker other than
>>>> possibly a
>>>> little more slop in the diff. Is it because I installed such low
>>>> gears?
>>>> Combination?
>>>> P.S. still does it after installing a NV4500 w/orig. Dana300. This NV
>>>> really sounds like a miniature jack hammer over 35 in neutral but
>>>> that's a
>>>> different post.
>>>> Regards,
>>>> Drink
>>>> 76 CJ7, GM 350, TPI, NV4500, DANA300
>>>> Dana30/AMC20 w1-pc axles, LockRite, 4.10s
>>
>>
>