g741.org

Yep, that appears correct Randy, it has T98 on a service tag on the trans. It also has the pto. Is that the same as the Borg-Warner T98 I wonder??

I have emailed Charles some photos so he can advise what to look for .

I've seen this situation many times also, the best fix for this is to replace the top cover assembly. What you have is easily recognized by excessive free play in the shift lever & can be visually seen by simply having a good external look at the outside of the tower. I hate to be the bearer of sad news, but the fix you have attempted is merely a band-aid on a death sentence. We've had countless transmissions come here with the same fix you have attempted, it is always short lived & if you don't go ahead & fix this thing right, further damage will result. New top cover assemblies for the early style trans are easy to install & not that costly. Way cheaper than ruining a whole transmission which will be the end result. You should also have a look inside to be sure the snap ring issue isn't the underlying cause of your problem as well, it very well could be. Trying to shift with the shift tower problem that you have had places tremendous stress on the main shaft sliding gears & synchronizer assemblies. Many times it is followed by the main shaft snap ring or groove failure as a result of this added stress.[/quote]


Please explain; I see no way for the new part I made ( if broken ) to fall into the case.

Rail man wrote:I've seen this situation many times also, the best fix for this is to replace the top cover assembly. What you have is easily recognized by excessive free play in the shift lever & can be visually seen by simply having a good external look at the outside of the tower. I hate to be the bearer of sad news, but the fix you have attempted is merely a band-aid on a death sentence. We've had countless transmissions come here with the same fix you have attempted, it is always short lived & if you don't go ahead & fix this thing right, further damage will result. New top cover assemblies for the early style trans are easy to install & not that costly. Way cheaper than ruining a whole transmission which will be the end result. You should also have a look inside to be sure the snap ring issue isn't the underlying cause of your problem as well, it very well could be. Trying to shift with the shift tower problem that you have had places tremendous stress on the main shaft sliding gears & synchronizer assemblies. Many times it is followed by the main shaft snap ring or groove failure as a result of this added stress.

Please explain; I see no way for the new part I made ( if broken ) to fall into the case.[/quote]

My best shot at an explanation is this.

Falling into the case isn't the issue. The original pin is a case hardened piece, this is why it's prone to breakage as the shift stub shaft ball groove starts to wear excessively. Sloop in the groove gets increasingly worse, pin eventually gets broken as a result or its bore in the tower gets worn or broken. All this creates a loose motion nightmare that brings the problem you had to light. I've seen many attempts at fixing it similar to what you described, in fact I have one sitting on the floor as we speak that has had a failed attempt at repair with a bolt just like you mentioned, never last long till the same issue is back to haunt. NOS early style shift tower/covers come with the shifter stub shaft installed, so all pieces that belong to this issue are brand new. In a hobby truck, this will last a good while before wear starts to be an issue. Bottom line is this, in the early trans this shifter situation & the mainshaft snap ring situation are 2 major design flaws. They are constant thorns in your flesh. The least amount of shifting abuse will bring out these issues much quicker, simply put, you must handle this transmission like running over an egg & not breaking it or you will have problems.

Getting back to the bolt fix, that bolt isn't hardened, will wear quickly along with the stub ball groove, loose motion reappears, same headache. It is at best simply a band-aid. There is a way to repair & virtually eliminate the shifter problem. Obtain an NOS tower/cover assembly, remove the stub shaft from the cover (will require complete tear down as it comes out from the inside). On the new assembly no wear exist in the ball socket, stub ball or its groove. Machine an identical groove in the opposite side of the ball. Drill & install a new pin in the shift tower to match up with the new ball groove. This gives twice the support to the shifter. Where all the pressure & wear tendancy was on 1 pin & groove before, it now has support on the other side to share the stress. Reassemble & install the unit. You will be amazed at the difference you will feel in shifting ease & confidence as well as the longivity of a modified ball / tower.

The later NP420 trans has a similar shifter set up to the modification mentioned above & the stub shaft can be removed in a few seconds from the outside making repair issues a breeze. It also addresses the snap ring issue & has a separate 2nd gear snap ring to share the stress so that the entire load isn't against just 1 ring. 2nd gear in the early trans has no snap ring. The NP420 units hardly ever give trouble, certainly much less than the early units. When a 420 comes in with a floopy shifter, 9 times out of 10 the whole unit is worn out & ready for a major overhaul. If rebuilt correctly, is not abused, & is maintained properly, they are good for another life just as long as original. The NP420 is a vastly improved unit over the early series. Of course internals will not interchange, but the whole trans will interchange perfectly from 1 truck to another. If you can get a good NP420, it's a very smart move to replace the early series trans in the older trucks prior to the B1 series.

Thank you Charles, I assume the PTO will fit the NP420.I would imagine a new top cover will be less expensive, are they available?

Rail man wrote:Thank you Charles, I assume the PTO will fit the NP420.I would imagine a new top cover will be less expensive, are they available?

Yes, the PTO will interchange. The last top cover I bought was around $100 I think. Then there's the expense of the modification. Personally I'd rather have a few $$$ in a 420, then you solve the snap ring issue at the same time.

I have a Canadian M37 transmission, rebuilt by a company in Canada. Let me know if anyone is interested. Sid

I still have two re-built (in Canada by Acme) Canadian transmissions if anyone is interested. Sid

MSeriesRebuild wrote:

Rail man wrote:Thank you Charles, I assume the PTO will fit the NP420.I would imagine a new top cover will be less expensive, are they available?

Yes, the PTO will interchange. The last top cover I bought was around $100 I think. Then there's the expense of the modification. Personally I'd rather have a few $$$ in a 420, then you solve the snap ring issue at the same time.

Thanks again, the modification to the top cover I can do but I,m not sure
if the snap ring is an issue on this trans. The repairer I made only took care of 75% of the problem.
When attending MV show\swap meet how do I identify the NP 420?

Rail man wrote:

MSeriesRebuild wrote:

Rail man wrote:Thank you Charles, I assume the PTO will fit the NP420.I would imagine a new top cover will be less expensive, are they available?

Yes, the PTO will interchange. The last top cover I bought was around $100 I think. Then there's the expense of the modification. Personally I'd rather have a few $$$ in a 420, then you solve the snap ring issue at the same time.

Thanks again, the modification to the top cover I can do but I,m not sure
if the snap ring is an issue on this trans. The repairer I made only took care of 75% of the problem.
When attending MV show\swap meet how do I identify the NP 420?

The fill/check plug on the 420 is on the right side of the case, the early is on the left. On the mainshaft seal/bearing retainer at the rear, the early will have an arm pointing to the left side that is there to keep the pin that holds the reverse fork shaft from sliding out of the case. The 420 doesn't have this arm on the retainer as it doesn't use this reverse fork shaft in the case. The reverse fork in the 420 is on the top cover giving it a total of 3 forks. The early trans only has 2 forks on the top cover. The shift tower is also notible. Look at the stub shaft on the early series trans, obviously it can't be removed from the outside. Look at this on the 420, a metal retainer is present. Upon pushing downward on the retainer & turning approximately an eighth turn, it releases from the pins allowing the stub shaft to lift straight up out of the tower. The later series NP420 is common to the B1 series of trucks which started during model year 1958.

Thank you again, now i'm on the hunt for a 420.