1987 Transmission shifting/leaking

1987BroncoProject

New member
Joined
Sep 16, 2011
Messages
19
Location
Georgia
Hi guys, I thought I might ask another question of you. The 1987 Bronco transmission is suspect. While driving down the highway or road, it sometimes feels like it slips out of drive into neutral, the engine revs but no power. Once it slows down a little, it goes back into drive automatically and you can step on the gas to speed up.

I thought maybe the transmission is slipping? Also, I got home and then there is some transmission fluid leaking on the driveway. Aamco said it only has 2 speeds and is not using all 4 speeds. Does the leak have something to do with it? Do I need a new transmission?

Thanks for any help you can give me.

 

Bully Bob

TOP GUN
Moderator
Joined
May 23, 2004
Messages
3,844
Location
Boulder City, Nevada (Las Vegas area)
"....and then there is some transmission fluid leaking on the driveway"

"Leaking" as we speak (maybe even a puddle.?)..., or signs of dribble over time..? :unsure:

Dribble is not really a good thing but...., leaking is bad. Meaning it will lower the req. amount of fluid needed.

"Aamco said it only has 2 speeds and...."

Did they NOT show you the leak...? :eek: /emoticons/[email protected] 2x" width="20" height="20" />

A leak.., therefore, low fluid, would cause slippage.

However, there may be other issues in the trannie that req. adjustment.

Worst case.... a re-build. :( /emoticons/[email protected] 2x" width="20" height="20" />

 
Last edited by a moderator:

1987BroncoProject

New member
Joined
Sep 16, 2011
Messages
19
Location
Georgia
Thanks BullyBob,

It is leaking, as in, there is a small puddle. I checked the trans and engine oil and both are at ok levels. Thing is, I don't know how to tell which it is. I looked under the car and it is on the trans pan but also higher up on the side of the engine as if it was the valve covers.

Anyway, I kept reading on Bronco Zone and learned a lot like, the Manual Level Position Sensor, and the ENGINE light being on temporarily, and the Rear Anti Lock Brake light being on all the time.

I saw a post by Miesk and learned that it is a good idea to "pull codes" key-on engine off, and key on engine on for starters. I should probably also get that MLPS switch thing too, hopefully at O'Reilly's or somewhere, right?

I can also replace the valve cover gaskets in case its the valve covers.

What do you think??

 

Bully Bob

TOP GUN
Moderator
Joined
May 23, 2004
Messages
3,844
Location
Boulder City, Nevada (Las Vegas area)
"I don't know how to tell which it is."

Trannie fluid is usually more clear... Eng. oil is usually darker after time. (some trannie fluids are red)

They smell different (trannie usually smells cleaner, so to speak)..., also, you can use the dipsticks to put a drop on a white paper. Get a drop off the bottom (leak) & compare.

---- A little oil spreads a long way under a moving veh. ----

It's dirty work but you can clean the underbelly. Wiping down is one way. Then see if you can trace the leak.

You may have an eng. oil leak..., and an unrelated trannie slippage issue.

I saw a post by Miesk and learned that it is a good idea to "pull codes" key-on engine off, and key on engine on for starters. I should probably also get that MLPS switch thing too, hopefully at O'Reilly's or somewhere, right?

I haven't worked with codes for a while so, those other fine folks will have to guide you on this.

I can also replace the valve cover gaskets in case its the valve covers.

I would hold off until you're sure they're failing.

However, you could tweek the bolts to insure they're snug. (don't over torque)

 

miesk5

96 Bronco 5.0
Staff member
Moderator
Joined
Oct 18, 2005
Messages
8,006
Location
Coronado, CA
yo 1987BroncoProject,

As BOB Advised so well!

LEAK DETECTION

Fluorescent Leak Detection

Employs an ultraviolet or UV/blue light inspection lamp and fluorescent dyes to find even the smallest leaks quickly and easily. It locates multiple leaks and those not found by any other method. Its lack of disadvantages explains why it is the most popular leak detection technique. In addition to diagnostics, it is the only preventive/programmed maintenance method that detects all refrigerant and fluid leaks.

Visual Inspection

This labor-intensive procedure is very time-consuming except for the largest, most obvious leaks. Some people lay newspaper down to try to locate the general area of the leak. They will check the color of the fluid to try to identify what system it is coming from, i.e., red for transmission fluid, green for coolant or orange, etc. However, it’s often difficult to pinpoint the exact source. Cannot be used for refrigerant leaks or for small leaks which evaporate right away. It’s difficult to detect clear liquids.

Soapy Water and Bubble Solutions

Although it’s inexpensive, this method has a number of serious drawbacks. In addition to being very time-consuming, it is not applicable to oil, hydraulics, transmissions and fuel. Only for refrigerant leaks.

Talcum Powder

Spraying foot powder on and around a suspect area may help you to find the leak if you’re lucky. But don’t run the engine, or you’ll make a real mess. This powder can also foul up carburetors. Only for oil leaks. I used to remove fan and run engine to find leak(s) source(s); stoppping eng when it reached norm op temp; best done in cold weather

Ion Detector ("Sniffer")

Detects only the general area of a refrigerant leak, not the exact location.This fragile device does not withstand hard use. In addition, it does not operate well in humid conditions. Only for refrigerant leaks.

Compressed Air

Used in water-cooling systems, it can damage hoses, radiators, and other components. It can actually cause additional leaks and enlarge existing ones. Only for coolant leaks. or get a pressure tester from local parts store loan a tool program; see my broncolinks.com site under ZZEngine, Cooling for LINKs such as at http://www.aa1car.com/library/coolant_leaks.htm

Identification; E4OD, AOD & C6 Pan Identification & Driver Side pics by Kenneth. Shift Indicator Patterns & Indicator pics (AOD, C6 & E4OD); AOD have 14 pan bolts, P-R-N-(D)-D-1 shifter pattern, note, OD is actually a (D) - pic by trigger; C6 have 17 pan bolts, P-R-N-D-2-1, shifter pattern - pic by miesk5; E4OD have 20 pan bolts; P-R-N-D-2-1 shifter pattern - pic by Chris A.

Source: by Chris A (blueoval78), trigger & miesk5 via miesk5 at Ford Bronco Zone Forums http://broncozone.com/topic/22732-1990-bronco-351/

Guessing it is an AOD

Trouble Shooting, COMPREHENSIVE; "...from the AOD service manual..."

Source: by duanemyhre at http://www.sccoa.com/forums/showthread.php?t=30511

====

SELF TEST COMPREHENSIVE & Connector Location pics, Bronco & Ford; "...The self-test plugs were mounted on the passenger side fender on 1985-86 EFI trucks; The self-test plugs are located along the driver's side fender behind the air filter box on 87-95 EFI trucks..."; miesk5 NOTE; Self-Test Input (STI) is the Pin in the Lt gray Connector and Signal Return Ground (STO/SIGRET) is Pin E in black Connector in 87-95; The engine temperature must be greater than 50°F (10°C) to pass the KOEO Self-Test and greater than 180°F (82°C) to pass the KOER Self-Test. Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accesories/lights, etc. Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch. Do Key On Engine Off (KOEO) portion first. Fix any codes from the KOEO test before you do the running test (KOER, key on, engine running). Look Codes up in my broncolinks.com site using the new Search function. .; miesk5 Note; Steve83 advises; "...If the CEL is burned out, connect CEL © to a 12V test light, and the light's other terminal to a 12V source on the same vehicle..." MIESK5 NOTE; C199 Self-Test Input (STI) (Gray) & C198 Diagnostic Link Connector (DLC) (Black)

Source: by BroncoJoe19 (Joe) at Ford Bronco Zone Forums

http://broncozone.com/topic/14269-code-reader/

post Code(s) found by KOEO & KOER

 

Members online

Latest posts

Forum statistics

Threads
21,503
Messages
125,394
Members
23,331
Latest member
Ole
Top