Jump to content

49 Roadmaster Dynaflow-howling on acceleration?


Recommended Posts

Hi, I have a 49 Roadmaster with a dynaflow, 45,000 original miles. It has a howl upon accelaration and sound drops off when coasting. Doesn't sound like a rear wheel bearing, it doesn't change when cornering or inducing side loads. I'm not too familiar with the torque tubes, the sound seems to come from the rear end and travel up the tube to the midsection of the car. Anybody have an idea of whether ring & pinion or carrier bearings would cause this, or is there a u-joint where the driveshaft meets the dynaflow that could cause this? It does not seem to be in the trans, I used both D and L and it doesn't matter, sound still there.

Thanks, Rick

Link to post
Share on other sites

How bad is it? My '53 has a bit of gear noise when gas is applied that goes away when coasting...did you check the gear oil? These things are famous for having transmission fluid leak through the torque tube, contaminating the gear oil. That's the first place I'd check.

Link to post
Share on other sites

Pinion bearing eh Bob? I believe my year has two races for the pinion bearings; is there any way to "adjust" them, or do they need to be replaced? I have the service manual and there are procedures in place, but I need real world advice. I suppose that means the whole rear has to come out of the car?

Link to post
Share on other sites

I'm not the one to give "real world" advise on changing the pinion bearings but I'm sure the rear needs to come out to do it. That's really not as ugly a job as you might think. Before I pulled the rear I'd check the rear bearings and the fluid level. It is possible you are leaking ATF into the rear. You can also pull the axles and carrier out with out removing the rear and check the pinion clearance for wear. I think they call out .0015 as max play.

It doesn't take much to make a rear noisy. I put a rear in my 55 Olds that had very minor pitting on the faces of maybe 6 teeth on the ring gear. It was VERY noisy on acceleration. You might want to check that first also. Rears are a *****.............Bob

Link to post
Share on other sites
  • 3 weeks later...

Well, did some work on the rear.......drained the fluid (didn't see any trans fluid leaking from the torque tube), re-filled and test drove. Howling on acceleration still there. It REALLY resonates around 50 mph. Quiet as a mouse when coasting. Ring and pinion teeth don't seem pitted. Would it be the gears, or the pinion bearing do you think?

Link to post
Share on other sites
  • 2 years later...
How bad is it? My '53 has a bit of gear noise when gas is applied that goes away when coasting...did you check the gear oil? These things are famous for having transmission fluid leak through the torque tube, contaminating the gear oil. That's the first place I'd check.

Hi,

I read your note and having same problem on a 51 roadmaster, thought I saw red fluid under differential. I will check this out. Sure did not look like 90 w

If leaking what seal is this

Thanks

Felix

Link to post
Share on other sites

It is your front torque tube seal. I guarantee it. Drill a 1/4" hole about three inches from the front of the pumpkin and there will be anywhere from a pint to a gallon of tranny fluid that drains out. The part is less than $15, but it takes me 4 hours to replace one in a 55 and it recently took me close to 7 hours on a 50 since there are more parts to remove.

Link to post
Share on other sites

Additionally, you'll want to make sure the prop shaft isn't scored. If so, you'll have to get it sleeved or it will continue to leak. On the other hand, if you drill the hole in the torque tube like Mike said, you can drain it regularly.

Link to post
Share on other sites
It is your front torque tube seal. I guarantee it. Drill a 1/4" hole about three inches from the front of the pumpkin and there will be anywhere from a pint to a gallon of tranny fluid that drains out. The part is less than $15, but it takes me 4 hours to replace one in a 55 and it recently took me close to 7 hours on a 50 since there are more parts to remove.

Mike,

Thanks for the info. I have a couple of questions.

The hole to be drilled is the tube connecting the tranny to the pumkin. This needs to be sealed after ????.

I planned on draining the pumkin and measuring fluid and refilling. I doubt the noise will go away as the damage to the bearings has been done ?????

I imagine we will have to replace the front torque seal as you stated, but would like to repair the noise too. What are your thoughts on this.

Will try to do the test this weekend

Thanks

Felix

Link to post
Share on other sites

I drill a 1/4" hole then tap it and install a small bolt. The bolt I use is a round head with Allen head, so it kinda blends in.

Doing only this is a stop-gap measure, but it will tell you how bad it is AND give you an inspection hole for the future.

Link to post
Share on other sites

Pull the differential cover and inspect the gears. This may also reveal how much transmission fluid that got into the rear. You should not have any side movement of the ring gear or deflection of the pinion gear when prying ( this will show if definitely bad, but not necessarily that they are good :rolleyes:). Pull the axle shafts, check the bearings and if ok, repack with grease and replace the seals.

After all that it may even be something obscure like the universal joint in the torque ball or even incorrect adjustment of the outer torque ball retainer.

Mike will tell you not to ask me about noises since the last time mine had a noise I was sure(!) it was from the rear, specifically the LR axle bearing since that the last thing I serviced...turned out it was the RF wheel bearing. :eek:

Willie

Link to post
Share on other sites
Pull the differential cover and inspect the gears. This may also reveal how much transmission fluid that got into the rear. You should not have any side movement of the ring gear or deflection of the pinion gear when prying ( this will show if definitely bad, but not necessarily that they are good :rolleyes:). Pull the axle shafts, check the bearings and if ok, repack with grease and replace the seals.

After all that it may even be something obscure like the universal joint in the torque ball or even incorrect adjustment of the outer torque ball retainer.

Mike will tell you not to ask me about noises since the last time mine had a noise I was sure(!) it was from the rear, specifically the LR axle bearing since that the last thing I serviced...turned out it was the RF wheel bearing. :eek:

Willie

Old Tank,

Great info to start with much appreciated

Link to post
Share on other sites
Pull the differential cover and inspect the gears. This may also reveal how much transmission fluid that got into the rear. You should not have any side movement of the ring gear or deflection of the pinion gear when prying ( this will show if definitely bad, but not necessarily that they are good :rolleyes:). Pull the axle shafts, check the bearings and if ok, repack with grease and replace the seals.

After all that it may even be something obscure like the universal joint in the torque ball or even incorrect adjustment of the outer torque ball retainer.

Mike will tell you not to ask me about noises since the last time mine had a noise I was sure(!) it was from the rear, specifically the LR axle bearing since that the last thing I serviced...turned out it was the RF wheel bearing. :eek:

Willie

Is that like someone jacking up the l/r to change the r/f tire??

Ben

Link to post
Share on other sites

Pull the differential cover? I'm confused.

I would have the car raised with a jack under the pumpkin keeping the body weight on the springs and jack stands under the frame. Then let the rear end turn. Use the service brake to stop the wheels and check the rear wheel bearings. They will tramp pretty good with no load. Stop them and hold the opposite wheel and let them start slowly, under control.

Don't get under the car unless its on a lift. A piece of 5 or 6 foot 3/8" threaded rod makes a good stethoscope and keeps you a safe distance. If the wheel bearing were OK, listen at other locations. I would lean toward the pinion because of the howl.

These 60 year old cars have a lot of mass to the heavy castings in the rear end, transmission, engine block, and other parts. And sometime during that 50 years they probably sat unattended for a few years. All those inner cavities are vented. The moisture in air will condense in droplets over the years and left a lot of water pooled in the bottom; ever take a rearend or transmission apart from a junkyard and see the water pour out? Your car might have come out of long term storage and driven with water and old grease for lube.That's a bearing killer and often neglected at the excitement of getting the engine running.

A couple of days ago I read about an engine "starting right up" after sitting in long term storage. Thinking about all those dry surfaces made me shiver like dragged fingernails across a blackboard. Lots of preparation work gets neglected on these stored cars and the damage happens fast or they break and get torn apart for restoration and never run again.

Those whom don't have a bad bearing and haven't changed fluids yet have a chance to do it before they get in deep.

My '60 had just a little squeak, squeak, at low speeds. I pulled the rear end and found no needle bearings in that U-joint inside the torque tube:

0409111515s.jpg

That was a couple of years ago when an owner of a "57 or '58 couldn't remove his rear because the joint broke and twisted the tail shaft spline. Glad I didn't want to live with that squeak!

It takes a lot to keep them bright wheels rolling.

Bernie

Edited by 60FlatTop (see edit history)
Link to post
Share on other sites
I drill a 1/4" hole then tap it and install a small bolt. The bolt I use is a round head with Allen head, so it kinda blends in.

Doing only this is a stop-gap measure, but it will tell you how bad it is AND give you an inspection hole for the future.

As suspected 1 pint of tranny fluid drained out into rear of torque tube. I did not have tie to pull pumkin fill plug to see if over filled but suspect it is. Hope to pull out rear end housing and hoping rear wheel bearings and check u joint hope pinion bearings are good and replace

torque tube seals. Where would you start from here

Edited by Felix (see edit history)
Link to post
Share on other sites

Think I would at this point just secure it very well up in the air and pull the whole rear end wheels and all straight backwards. Clean the frame and pan areas real good, paint and then put all my attention on the rear end. Out to the car you have access to the torque tube back. Take everything apart, clean and inspect, new seals and bearings throughout, paint components, springs, arm strong shocks then reinstall. All present and future problems eliminated.

This reminds me of an apartment manager I once knew. When he first took the job he planned to only go to someones apartment if and only if they would call about a persistent problem Well it was an old building and he soon realized that most of his trips and there were many, were usually plumbing and faucet related. So after beating himself up over and over on plumbing issues, he decided he would blitz the entire building and all units in a one week campaign and change all the faucets and shut off valves in kitchen and bathrooms. Well upon doing so all the phone calls suddenly stop and he was never again bothered with reoccurring and persistent problem calls.

Link to post
Share on other sites
  • 2 weeks later...

Well opened up pumkin after draining found all tranny fluid that looked like metal flake paint. Gears look ok. Painted with red grease and looks like good tooth contact.

Can see evidence of white lead paint to check contact. I need some ??

Also noticed blue permatex silcone where someone has removed the pumpkin

Manual saying to flush out with 10W motor oil. Will do 2 times and refill with fresh 90W also have some 600W from my Model A might mix a little,

as my juicy metalflake oil has most likely wasted all bearings. Looking for a spare 51 Roadmaster rear not sure yet if 3.6 or 3.9

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...